Patent Application
20240366640
The present invention relates to the development of lyophilized formulations with TH-302 and belongs to the technical field of pharmaceutical formulations.
TH-302, a 2-nitroimidazole prodrug, is a selective hypoxia-activated DNA alkylating agent with high cytotoxicity that was designed and synthesized by investigators from Threshold Pharmaceuticals Inc. in 2006 (WO2007002931A2, Phosphoramidate alkylator prodrugs). It can be converted into dibromoisophosphamide chlormethine with alkylating-agent activity in hypoxic areas of tumors or upon activation with an acid, but is almost inactive under normoxic or normal pH conditions.
Investigators from Threshold Pharmaceuticals Inc. designed and developed preliminary lyophilized formulations and injection formulations in 2007 (WO2008083101A1, Phosphoramidate alkylator prodrugs for the treatment of cancer), and administered them in phase I clinical trials:
A solution (20 mL) of TH-302 (100 mg) and sucrose (1 g) was added to a lyophilized vial and lyophilized to produce a lyophilized unit dosage form of TH-302 with a drug load of less than 5 mg/cm3. For purposes of human administration, the unit dosage form was dissolved in 5% dextrose injection and an appropriate amount of this solution was administered to the patient.
TH-302 was dissolved in anhydrous ethanol to produce a pharmaceutically acceptable liquid formulation containing 5% TH-302. As used herein, a solution of 5% TH-302 contains 5 g of TH-302 in 100 mL of a solvent (e.g., ethanol).
The follow-up dose regimen for the human patients in the Phase I clinical trial of TH-302 uses a lyophilized formulation. The TH-302 lyophilized formulation for injection is prepared in a 100 mL glass vial with a drug load of 100 mg/100 ml and stored under a controlled temperature of 2-8° C. When in use, the vial containing the lyophilized formulation was injected with 250 mL of 5% dextrose and infused intravenously via an infusion pump within 30 minutes.
Investigators from Threshold Pharmaceuticals Inc. designed and developed the injection formulations in 2009 (WO2010048330A1, Treatment of cancer using hypoxia activated prodrugs):
liquid formulations, which contain 50 mg/ml to about 300 mg/ml of TH-302, nonionic surfactants (such as Tween 80), and ethanol as a carrier, and may further contain dimethylacetamide.
Clinical trials were started from 2007 and continued until now, covering a variety of solid tumors and blood cancers, and the administration regimens are also diverse: different doses of TH-302 being used alone or in combination with other cancer treatment drugs. At present, there are 27 clinical trials using TH-302 as a therapeutic drug to treat various cancers and tumors registered in the United States (NCT02402062, NCT02020226, NCT02076230, NCT01381822, NCT02093962, NCT01440088, NCT02255110, NCT02342379, NCT01864538, NCT01149915, NCT02433639, NCT00743379, NCT01485042, NCT01721941, NCT02047500, NCT00742963, NCT01497444, NCT00495144, NCT01746979, NCT01144455, NCT01403610, NCT01522872, NCT01833546, NCT02598687, NCT03098160, NCT02496832, NCT02712567). These clinical trials show that TH-302 is a broad-spectrum anti-cancer drug candidate.
After conducting the above-mentioned phase I/II clinical trials, investigators from Threshold Pharmaceuticals Inc. have found that the effective doses of TH-302 for treating various indications were as follows (WO2012135757A2, Methods for treating cancer):
According to the above effective doses, for an ordinary person (height: 175 cm, weight: 75 kg), the corresponding equivalent body surface area BSA (m2)=([height (cm)×weight (kg)]/3600)1/2=1.90, and then the corresponding dose is 228-1273 mg! In this case, if a lyophilized formulation with a drug load of less than 5 mg/cm3 is used (20 mL of an aqueous solution containing 100 mg of TH-302 and 1 g of sucrose was added to a 50 ml lyophilized vial and lyophilized to produce a lyophilized unit dosage form of TH-302, and the drug load is less than 5 mg/cm3), at least 3 vials are needed; and if it is used at a higher dose, 13 vials would be needed. This would be inconvenient for clinical use and also involves excessively high medication costs for patients.
For the above reasons, in most of the subsequent phase II/III clinical trials, investigators from Threshold Pharmaceuticals Inc. have used concentrated injections (WO2015013448A1, Treatment of pancreatic cancer with a combination of a hypoxia-activated prodrug and a taxane):
TH-302 (concentrate for solution for administration) for use in the trials is a sterile liquid formulation of TH-302. It is formulated with 70% anhydrous ethanol, 25% dimethlyacetamide, and 5% polysorbate 80. It will be supplied by the sponsor in a 10-mL glass vial with a rubber stopper and flip-off seal. TH-302 drug product is a clear, colorless to light-yellow solution, essentially free of visible particulates. Each single use vial contains a nominal fill volume of 6.5 mL of TH-302 drug product (corresponding to 100 mg/mL) for a nominal total of 650 mg of TH-302 and will be labeled clearly. The labels disclose the lot number, route of administration, required storage conditions, sponsor's name, and appropriate precautionary labeling as required by applicable regulations. Dilution prior to administration is required per the pharmacy manual.
TH-302 drug product will be diluted prior to administration with commercially available 5% dextrose in water to a total volume of 500 mL (1000 mL for total dose of ≥1000 mg) per administration to obtain the desired final concentration. Each dose of TH-302 will be prepared with 5% dextrose aqueous solution not containing di(2-ethylhexyl)phthalate (non DEHP), and administered via intravenous drip using an intravenous infusion administration apparatus, not containing DEHP.
Apparently, it is more convenient to use concentrated injections with a drug load of 100 mg/ml in clinical trials than to use lyophilized formulations with a drug load of less than 5 mg/cm3: for the former, a 10 ml gauge vial is adequate to meet the medication requirements of most patients, while for the latter, to meet the medication requirements of most patients, 13 commonly-used vials of 100 ml gauge are required!
However, investigators of Threshold Pharmaceuticals Inc. have found that the above-mentioned concentrated injection with a drug load of 100 mg/ml (i.e., the concentrated injection of TH-302 formulated with 70% anhydrous ethanol, 25% dimethylacetamide, and 5% polysorbate 80) contains a large amount of dimethylacetamide. This adjuvant that can increase drug solubility and improve the stability of injections are susceptible to cause allergies after infusion into the human body (WO2015013448A1, Treatment of pancreatic cancer with a combination of a hypoxia-activated prodrug and a taxane):
TH-302 administration reactions (which are mainly induced by dimethlyacetamide) have been observed. These reactions have been characterized by lip swelling and urticaria that responded to steroid and antihistamine treatment. It is recommended that a steroid such as dexamethasone (or equivalent) be included in the antiemetic regimen prior to administration. Symptoms and signs of hypersensitivity include fever, myalgia, headache, rash, pruritus, urticaria, angioedema, chest discomfort, dyspnea, coughing, cyanosis, and hypotension. If the nature and the severity of the reaction require termination of treatment, it should be determined whether the reaction may be an immunoglobulin E mediated process or not. If there are symptoms such as upper airway obstruction or hypotension that suggest anaphylaxis or an anaphylactoid reaction, treatment with an antihistamine (e.g., diphenhydramine 25 to 50 mg oral, intramuscular, or slow i.v., or equivalent) and a low dose of steroid (e.g., hydrocortisone, 100 mg i.v. or equivalent) should be considered by the investigators as appropriate. If the event is clearly anaphylaxis, epinephrine (1/1000, 0.3 to 0.5 mL administered subcutaneously, or equivalent) should be considered as well as standard treatment. In the case of bronchospasm, inhaled β-agonist should be considered. Idiosyncratic reactions may also be treated with an antihistamine and a low dose of steroids depending on their severity. Reactions to the administration of TH-302 should be assessed and treated in a similar manner. For all reactions to TH-302, the investigator should consult with the Medical Monitor to determine the appropriate course of action for future treatment.
High-concentration concentrated TH-302 injections have solved the problem of low drug load in lyophilized formulations. However, due to the use of the above-mentioned adjuvants that may cause adverse reactions, related adverse reactions may occur in clinical trials to result in increased risk of medication for patients.
The lyophilized formulations that have been currently developed by dissolving TH-302 with water and a sucrose solution followed by lyophilization are free of other adjuvants. However, as the drug content of the solution before lyophilization is too low, it is impossible to afford a lyophilized formulation with a high drug load that can meet the requirements for use in clinic trials and subsequent commercialized production or sales.
To solve the above-mentioned problems in reality, there remains a need to develop a lyophilized formulation of TH-302 with a high drug load and a solution for such lyophilized formulation by the technical experts in the relevant field.
After many experiments and continuous optimization, the inventors of this invention have proposed a new high-drug-concentration solution formulation for producing lyophilized formulations containing TH-302 and other similar drugs, and related lyophilized formulations and methods thereof.
In order to facilitate understanding of the essence of the present invention, the inventors' research process is briefly described below.
In order to screen suitable combinations of solvents and adjuvants to prepare a high-concentration
solution, the inventors initially conceived of modifying the concentrate injection with a rug load of 100 mg/ml developed by Threshold Pharmaceuticals Inc., i.e., the concentrated injection of TH-302 formulated with 70% anhydrous ethanol, 25% dimethlyacetamide, and 5% polysorbate 80:
Note: ratios in expressions “1% ethanol aqueous solution”, “20% ethanol aqueous solution”, “1% N,N-dimethylacetamide aqueous solution”, “1% polyethylene glycol aqueous solution”, and “1% Tween 80 aqueous solution” are all volume-based ratios.
By performing numerous experiments, the inventors have confirmed that it is impossible to develop a highly-soluble solution that meets the requirements to make a TH-302 lyophilized formulation with a high drug-load via lyophilization by using merely ethanol, aqueous solutions at different pH values or ethanol+water as the solvent according to Threshold.
After many attempts, the inventors have found that TH-302 has low solubility in water or tert-butanol alone; however, they have surprisingly found that TH-302 has remarkably increased solubility in a mixed solvent of water and tert-butanol, and the solubility is highly dependent on their mixed ratios. The solubility data of TH-302 in different mixed solvents of tert-butanol+water or of tert-butanol+ethanol are shown in Table 2 below.
Note: the ratios of mixed solvents in Table 2 refer to volume ratios, and TH-302 is purchased commercially.
Tert-butanol is a colorless crystal, easily supercooled, and becomes liquid in the presence of a small amount of water. It has a camphor-like odor and is hygroscopic. Its Chinese names include 2-methyl-2-propanol, tert-butanol, trimethylmethanol, etc. Since it has a melting point of 25.7° C., it is a colorless transparent liquid or colorless crystal at room temperature.
Generally speaking, tert-butanol has the following characteristics:
1. High freezing point. Pure tert-butanol may crystallize at room temperature (25° C.), and can also be frozen at a few degrees below zero after being mixed with water; both pure tert-butanol and mixture of tert-butanol with water can be completely frozen in existing lyophilizers.
2. Tert-butanol has a relatively high vapor pressure. High vapor pressure is advantageous for sublimation and requires less lyophilizing time.
3. Tert-butanol is capable of being mixed with water in any ratio. This is extremely important because it enables increase of the solubility of some lipid-soluble drugs in water; and for some drugs that are unstable in aqueous solutions, adding an appropriate amount of tert-butanol can inhibit the decomposition of the drugs and enhance their stability.
4. Tert-butanol is easy to be lyophilized, and has low residual content in the formulation. During lyophilization, most of the tert-butanol may be sublimated in one drying stage, and thus its residual content in the formulation is very low.
5. Tert-butanol forms needle-like crystals during freezing, and thus can change the crystallization mode of the solute and facilitate sublimation. The tert-butanol-water co-solvent formed when a small amount of tert-butanol is added to water can change the crystallization state of water; and the needle-like crystals formed during freezing have large surface area. The sublimation of ice crystals leaves tubular channels, which allow the flow resistance for water vapor largely reduced and sublimation rate significantly increased. Accordingly, tert-butanol can be used to accelerate mass transfer during the freeze-drying processes.
In view of the above characteristics, it can be seen that tert-butanol+water as a solvent can be used for preparing a solution comprising a high-concentration compound of formula I, and tert-butanol itself is also suitable for use as an adjuvant for lyophilization owing to its intrinsic properties.
From the results of the tert-butanol-water mixed solvent shown in Table 2, it can be deduced that TH-302 has relatively low solubility in aqueous solutions; as the concentration of tert-butanol in the tert-butanol aqueous solution increases, the solubility of the active pharmaceutical ingredient increases; it is estimated that the highest solubility is reached at 70% tert-butanol aqueous solution (V/V), and then the solubility decreases as the concentration of tert-butanol in the tert-butanol aqueous solution increases.
In light of this, the inventors have proposed a scheme in which a solution with high-concentration TH-302 is obtained by using tert-butanol+water as a solvent according to the present invention and adding suitable excipient(s), and further developed lyophilized formulations with a high drug load of TH-302 or analogues thereof based on this formulation.
The inventors have further conducted experiments to investigate the effects of solvents with different volume ratio of tert-butanol on the solubility of TH-302, and the solubility data obtained are shown in Table 3 below.
Note: the ratios of mixed solvents in Table 3 refer to mass ratios, and TH-302 was synthesized by the applicants in small quantities.
Based on the above preliminary experiments, the present invention provides the following high-concentration solution containing TH-302 or analogs thereof.
A solution comprises a compound of the following formula I, water and tert-butanol,
Further, the present invention also provides a solution for preparing a lyophilized formulation with a high drug load, comprising a compound of the following formula I, water, tert-butanol and an excipient:
Since water and tert-butanol can be miscible in any ratio, in order to improve the solubility of TH-302 and other similar compounds, the volume percentage of tert-butanol relative to the solution is 1-99%, preferably 5-95%, and more preferably 30-60%; or
Here, the volume percentage of tert-butanol relative to the solution being 1%-99% corresponds to the tert-butanol content of 7.85-777.15 mg/ml in the solution; specifically, when the volume percentage of tert-butanol relative to the solution is 1%, the tert-butanol content in the solution is 7.85 mg/ml. The conversion factor is the density of tert-butanol. Here, the density of tert-butanol used by the applicant is 0.785 g/ml. In actual practice, the densities of tert-butanol products from different manufacturers are different under different temperatures, generally between 0.775 and 0.786 g/ml.
The solution for preparing a lyophilized formulation with a high drug load according to the present invention comprises at least one excipient.
The term “pharmaceutically acceptable excipient” refers to any additive or carrier that may contribute to the stability of active pharmaceutical ingredients in the formulation. During the preparation process of the lyophilized formulation, it is essential to add an excipient or a lyo-protectant to a solution used for lyophilization.
Some drug solutions can be successfully freeze-dried in vacuum, while others would quickly collapse or be melt into oily substances after lyophilization. In order to obtain stable lyophilized formulations by successfully lyophilizing certain drug solutions, some excipients that do not react with the drugs need to be added. Such excipients per se will not be sublimated in the sublimation stage of the lyophilizing process; instead, they can be directly lyophilized into skeletons and thus play a role of giving form; the drugs can be directly adsorbed on or filled in the gaps of the skeletons; or they can improve the solubility and stability of the lyophilized products, or they can enable the lyophilized products to have an aesthetical shape, etc. It is required to add some additional substances into the liquid formulations. The additional substances are collectively called “lyo-protectants”, and sometimes they are also called fillers, bulking agents, excipients, buffers, base materials, skeletons, etc. In general, lyo-protectants must be chemically inert to the drug solution.
Depending on their chemistry, lyo-protectants can be classified into the following categories:
The degree of polymerization (molecular weight) of the above-mentioned polymers is in a broad range. Polysorbates and polyethylene glycols are cited as the examples.
Polysorbate may have an average molecular weight ranging from about 500 g/mol to about 1900 g/mol, preferably from about 800 g/mol to about 1600 g/mol, and more preferably from about 1000 g/mol to about 1400 g/mol. Non-limiting examples of polysorbates include: polysorbate-20, polysorbate-21, polysorbate-40, polysorbate-60, polysorbate-61, polysorbate-65, polysorbate-81, polysorbate-85 and polysorbate-120. Preferred polysorbates include polysorbate-20, polysorbate-80, and a mixture thereof.
Polyethylene glycols (PEGs) may have an average molecular weight ranging from about 200 g/mol to about 600 g/mol, preferably from about 200 g/mol to about 500 g/mol, and more preferably from about 200 g/mol to about 400 g/mol. Non-limiting examples of PEGs include: PEG200, PEG300, PEG400, PEG540 and PEG600.
Poloxamer has a general formula of HO(C2H4O)n(C3H6O)b(C2H4O)cH, wherein a and c are in the range of 2-130 and b is in the range of 15-67. It contains 81.8±1.9% of polyoxyethylene and is a polyoxyethylene polyoxypropylene ether block copolymer. It has different brands: poloxamer 182, poloxamer 184, poloxamer 188, and poloxamer 407, which correspond to polymers with different molecular weights, such as Poloxamer 188 having a molecular weight of 7680-9510.
The lyo-protectant serves many functions, which are specifically summarized as follows.
Microorganisms such as bacteria and viruses need to grow and reproduce in particular culture media. However, the microorganisms are difficult to be separated from the culture media and thus may be successfully lyophilized in these culture media. Examples of culture media are broth, skim milk and protein, etc.
Some lyophilized formulations have very low concentration and minor dry matter content. During lyophilization, the dried components will be taken away by the sublimation airflow. In order to increase the drug concentration and the dry matter content to enable the lyophilized products to form relatively ideal agglomerates, it is necessary to add fillers to keep the concentration of the solid matter within a certain range. These fillers or excipients include sucrose, lactose, inositol, skim milk, hydrolyzed protein, dextran, sorbitol, polyvinylpyrrolidone (PVP), etc.
Some biologically active substances are particularly fragile and may be injured owing to physical or chemical factors during freezing and drying. Therefore, some protective agents (for example, dimethyl sulfoxide, glycerol, dextran, saccharides and PVP) need to be added to reduce damage during freezing and drying.
Adding certain substances (e.g., mannitol, glycine, dextran, xylitol and PVP) can increase the disintegration temperature of the product and make it easy to be lyophilized.
In order to change the pH of the lyophilized formulation to increase the eutectic point to facilitate lyophilization, sodium bicarbonate, sodium hydroxide, or the like may be added.
For the purpose of improving the storage stability of the product, increasing the storage temperature and prolonging the storage period, some antioxidants such as vitamin C, vitamin E, amino acids, sodium thiosulfate, thiourea, lecithin and hydrolyzed protein may be added.
Adding certain substances (e.g., amino acids, vitamin K, vitamin C, thiourea, sulfite compounds, and sodium aspartate) can eliminate free radicals and increase the stability of the lyophilized product.
It can be found that a single compound can play multiple roles as a lyo-protectant (excipient).
According to the properties of the drug of the present invention, the lyo-protectant (excipient) is selected from saccharides, polyols, polyvinylpyrrolidones, proteins, poloxamer or a combination thereof.
The saccharide is selected from sucrose, dextran, cyclodextrin, maltodextrin, trehalose, lactose, maltose, and glucose.
The polyol is selected from the group consisting of glycerin, sorbitol, mannitol, inositol, ethylene glycol, polyethylene glycol (PEG), polysorbate, and adonitol.
The protein is selected from albumin, preferably bovine serum albumin and human albumin.
The poloxamer is selected from poloxamer 182, poloxamer 184, poloxamer 188, and poloxamer 407.
Preferably, the excipient is selected from PVP K12, sucrose, mannitol, albumin or a combination thereof.
Generally speaking, excipients of the same type can be combined, and the excipients that do not react with each other and with drugs can be combined. The combination should meet the drug compatibility requirements.
In particular, the excipient is selected from sucrose and mannitol; and the content of sucrose or mannitol in the solution is in the range of 20-300 mg/ml, preferably in the range of 40-100 mg/ml, more preferably in the range of 60-80 mg/ml, and further preferably in the range of 60-70 mg/ml.
Generally only one of sucrose and mannitol is used, but in some special cases, sucrose and mannitol can also be mixed used. In the preferred embodiments of the present invention, only mannitol or sucrose is used.
Analogously, the mass ratio of TH-302 in the solution for preparing the lyophilized formulation with a high drug load to the excipient(s) is in the range of 1: (0.5-20), preferably in the range of 1: (1-15), more preferably in the range of 1: (2-12.5), and further preferably in the range of 1:(5-10).
The mass ratio of TH-302 and other similar compounds to the excipient is the drug loading ratio of the solution for lyophilization. According to the lyophilized state of the above-mentioned excipients (lyo-protectants, fillers, or skeletons), it can be seen that the lyophilized body after lyophilization has skeletons obtained from the excipient(s), and the drug(s) will be adsorbed on or loaded onto the skeletons. Thus, the drug loading ratio of the drug solution prior to lyophilization, i.e., mass ratio of TH-302 to the excipient(s), is an important index.
Appropriate drug loading ratio means that after lyophilization of the lyophilized formulation, the drug is evenly adsorbed on the skeletons, and the drug will be well distributed in the gaps and pore surfaces of the skeletons; thus, during subsequent reconstitution (with 5% dextrose injection, physiological saline, etc.), the lyophilized formulation can be rapidly and well dissolved to be ready for injection administration.
“Pharmaceutically acceptable buffer” refers to weak acids or bases that allow the pH value of the solution to be maintained at an almost constant level and are used to enhance the stability of the active pharmaceutical ingredient in the solution.
The solution for preparing the lyophilized formulation with high drug load according to the present invention can also comprise at least one buffer, and the buffer is selected from the group consisting of citrate buffer, borate buffer, lithium lactate, sodium lactate, potassium lactate, calcium lactate, lithium phosphate, sodium phosphate, potassium phosphate, calcium phosphate, lithium maleate, sodium maleate, potassium maleate, calcium maleate, lithium tartrate, sodium tartrate, potassium tartrate, calcium tartrate, lithium succinate, sodium succinate, potassium succinate, calcium succinate, lithium acetate, sodium acetate, potassium acetate, calcium acetate, or a mixture thereof.
Preferably, the buffer used in the solution for preparing the lyophilized formulation with high drug load according to the present invention is at least one citrate buffer. Non-limiting examples of suitable citrate buffers include: lithium citrate monohydrate, sodium citrate monohydrate, potassium citrate monohydrate, calcium citrate monohydrate, lithium citrate dihydrate, sodium citrate dihydrate, potassium citrate dihydrate, calcium citrate dihydrate, lithium citrate trihydrate, sodium citrate trihydrate, potassium citrate trihydrate, calcium citrate trihydrate, lithium citrate tetrahydrate, sodium citrate tetrahydrate, potassium citrate tetrahydrate, calcium citrate tetrahydrate, lithium citrate pentahydrate, sodium citrate pentahydrate, potassium citrate pentahydrate, calcium citrate pentahydrate, lithium citrate hexahydrate, sodium citrate hexahydrate, potassium citrate hexahydrate, calcium citrate hexahydrate, lithium citrate heptahydrate, sodium citrate heptahydrate, potassium citrate heptahydrate, and calcium citrate heptahydrate.
The solution for preparing the lyophilized formulation with a high drug load according to the present invention can also comprise at least one pH regulator.
The pH regulator of the present invention refers to a buffer substance or buffer solution used to appropriately adjust the pH changing with acid or alkali. The pH regulator includes, but is not limited to, hydrochloric acid, sodium hydroxide, triethanolamine, phosphoric acid, disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate; or phosphoric acid, citric acid, lactic acid, tartaric acid, succinic acid, fumaric acid, malic acid, sodium bicarbonate, sodium carbonate or a mixture thereof. The content of the pH regulator to be added is such that the pH value of the solution is in the range of 4-9, preferably in the range of 6-8.
Since TH-302 and its analogs are usually acidic (the preparation process of the compound involves an acidic environment and slight hydrolysis, the active pharmaceutical ingredient prepared or purchased will be acidic), the pH regulator is preferably selected from a base such as sodium hydroxide, triethanolamine, sodium bicarbonate, and sodium carbonate, or an alkaline salt.
Of course, it is also possible that the pH of TH-302 and its analogs is alkaline due to other factors. In this case, an acid or acidic salt (such as ammonium sulfate and ammonium chloride) needs to be added for adjusting the pH.
The compound of the following formula I is selected from
and more preferably TH-302.
The specific synthesis method of the compound of formula I and the corresponding spectral data are disclosed in WO2007002931 (corresponding to Chinese publication CN101501054A), which is incorporated herein by reference in its entirety.
For the relevant physiochemical properties and biological activities of the compound of formula I and the three specific compounds, please refer to the patents owned by Threshold Pharmaceuticals Inc. (such as WO2016011195A2, WO2004087075A1, WO2007002931A1, WO2008151253A2, WO2009018163A1, WO2009033165A2, WO2010048330 A2, WO2012142520A1, WO2008083101A2, WO2020007106A1, WO2020118251A1, WO2014169035A1, WO2013116385A1, WO2019173799A2, WO2016081547A1, WO2014062856A1, WO2015069489A1, WO2012006032A2, WO2018026606A2, WO2010048330A2, WO2015171647A1, WO2013096687A1, WO2013126539A2, WO2013096684A2, WO2012009288A2, WO2012145684A2, WO2016014390A2, WO2019055786A2, WO2012135757A2, WO2015013448A2, WO2016011328A2, WO2013177633A2, WO2016011195A2, and WO2015051921A2), which are incorporated herein by reference in their entirety.
The three preferred compounds have the same or similar physiochemical properties to TH-302.
The present invention provides a solution for preparing a lyophilized formulation with a high drug load, comprising
The present invention provides a solution for preparing a lyophilized formulation with a high drug load, comprising
The present invention provides a solution for preparing a lyophilized formulation with a high drug load, consisting of
In the above-mentioned solution for preparing a lyophilized formulation with a high drug load, wherein the mass ratio of the compound to sucrose or mannitol is 1:2, 1:3, 1:3.5, 1:4, 1:5, 1:5.333, 1:5.6, 1:6, 1:1.67, 1:7, 1:8, 1:8.235, 1:8.75, or 1:9.375.
Of course, buffers, pH regulators or other auxiliary materials for the lyophilized formulations can also be added according to the above illustrations and depending on the properties of the specific compound of formula I.
Apparently, if other substances (environmental substances) are detected due to contact with or contamination of containers, pipes, and tools during the preparation of the solution, they do not belong to the category of such auxiliary materials. Similarly, tert-butanol, sucrose/mannitol, and the raw materials of the compound of formula I are inevitably doped with impurities or other substances involved in the environment (environmental substances). These impurities or environmental substances are also not included in said category of auxiliary materials.
The contents of all the other substances (environmental substances) detected due to contact with or contamination of containers, pipes, and tools and the impurities or the other substances involved in the environment (environmental substances) inevitably doped in tert-butanol, sucrose/mannitol, and the raw materials of the compound of formula I should be within the statutory limits or comply with quality standards (pharmaceutical grade, medical grade or equivalent quality standards) of the corresponding products.
Apparently, if other substances (environmental substances) are detected due to contact with or contamination of containers, pipes, and tools during the preparation of the solution, they do not belong to the category of such auxiliary materials. Similarly, tert-butanol, sucrose/mannitol, sodium bicarbonate and the raw materials of the compound of formula I are inevitably doped with impurities or other substances involved in the environment (environmental substances). These impurities or environmental substances are also not included in said category of auxiliary materials.
The contents of all the other substances (environmental substances) detected due to contact with or contamination of containers, pipes, and tools, and the impurities or the other substances involved in the environment (environmental substances) inevitably doped in tert-butanol, sucrose/mannitol, and the raw materials of the compound of formula I, should be within the statutory limits or comply with quality standards (pharmaceutical grade, medical grade or equivalent quality standards) of the corresponding products.
Therefore, the above-mentioned expression “consisting of . . . ” refers to substances that are intentionally or artificially added during preparation (these substances are essential to be contained and can be detected by analytical testing instruments). In addition to these substances, there are no other intentionally or artificially added substances. However, there will still be inevitablely trace amounts of impurities, environmental substances, or the like.
The above contents explain the constituents (formulation) of the solution for preparing the lyophilized formulation with a high drug load, and its use is briefly described below.
The solution provided above is only used as an intermediate semi-finished product for preparing the lyophilized formulation with a high drug load and cannot be used for clinical formulations. Generally speaking, it is readily prepared for use at the production site; that is, it is prepared in a liquid-formulating container and directly filled into lyophilized vials, and then sent into the lyophilizing production equipment in batches for lyophilization.
Therefore, it should be ensured that the solution for preparing the lyophilized formulation with a high drug load is stable after preparation and during production and waiting process for being lyophilized in the lyophilizing equipment, it should be stable at room temperature for at least 8 hours, and preferably for 24 hours or even 72 hours, or for 120 hours.
This is because the solution needs to be filtered and filled before it is sent into a lyophilizer for lyophilization after preparation. Filtration and filling are usually completed within 8-12 hours and are generally performed at room temperature. Despite this, the subsequent lyophilization is conducted at low temperature and it takes 20-60 hours for a large-scale lyophilizer or lyophilizing system to cool the large amount of drug liquid filled in vials to the set low temperature (−20° C. to −55° C.). Thus, the drug solution for the lyophilized formulation should be stable within a certain period of time and at room temperature. After experiments, the inventors have validated that the drug solution for the lyophilized formulation of TH-302 provided by the present invention has appropriate stability.
The present invention also provides use of a solution for preparing the lyophilized formulation with a high drug-load. The solution is suitable for use as a lyophilized formulation solution and is used for preparation of the lyophilized formulation by a lyophilization process.
Based on the above-mentioned solution for preparing the lyophilized formulation with a high drug-load, the present invention can provide lyophilized formulations with a high drug-load.
A lyophilized formulation is prepared using the above-mentioned solution for preparing a lyophilized formulation with a high drug-load as a lyophilized formulation solution by a lyophilization process.
A lyophilized formulation comprises a compound of the following formula I, an excipient and residual solvent components,
A lyophilized formulation comprises a compound of the following formula I, an excipient, residual solvent components and a pH regulator,
A lyophilized formulation comprises a compound of the following formula I and an excipient,
Here, the drug load of the compound of formula I in the lyophilized formulation being greater than 5 mg/cm3 and less than or equal to 555.55 mg/cm3, and the drug load of the compound of formula I in the lyophilized formulation being greater than or equal to 4.55 mg/cm3 and less than 500 mg/cm3 denote two different situations.
After extensive experiments, the applicants have found that in the case of using 50 ml vial and a maximum filling volume of 25 ml, for different lyophilized processes of lyophilizing the above-mentioned lyophilized formulation solution with a high drug load to afford a lyophilized formulation, there is a change of less than 10% between the volume of the pre-lyophilization solution and the external volume of the lyophilized formulation solid; the volume may be increased by 10% due to expansion of the lyophilized cake after lyophilization, or it may be reduced by 10% due to collapse of the powder cake. It is calculated based on the content of the compound of formula I in the lyophilized formulation solution with a high drug load before lyophilization being greater than or equal to 5 mg/ml and less than or equal to 500 mg/ml and the maximum change of 10% that, the volume is 1.1 times that of the original volume due to the expansion, or is 90% of the original volume due to the collapse. Taking the volume of the collapsed powder cake after lyophilization being 90% of the original volume as an example, the maximum drug load of the powder cake here is calculated to be 5/0.9=5.55 to 500/0.9=555.55. Depending on the process, there may be a situation where the volume does not change. In this case, the drug load is ranging from 5 to 500. The two ranges are combined to be 5 to 555.55; that is, the drug load of the compound of formula I in the lyophilized formulation is greater than 5 mg/cm3 and less than or equal to 555.55 mg/cm3.
Analogously, when the volume is increased due to the expansion of the lyophilized cake, the drug load of the compound of formula I in the lyophilized formulation is greater than or equal to 4.55 mg/cm3 and less than 500 mg/cm3.
The drug load of the lyophilized formulation provided by the present invention refers to the amount of the compound of formula I as the active pharmaceutical ingredient contained per unit volume; and the volume here refers to the total external volume of the drug in the unit packaging kit, including the internal voids of the drug. For example, a 20 ml of the lyophilized solution in a 100 ml lyophilized vial contains 500 mg of the drug. After the pre-lyophilization solution has been lyophilized, the 20 ml of the solution will be frozen into a loose and porous lyophilized formulation. When the bottom area of the inner space of the lyophilized vial is measured as s, and the height of the lyophilized formulation in the lyophilized vial as h, then the total external volume of this unit-packaged lyophilized formulation is sh; since 500 mg of the active pharmaceutical ingredient is loaded, its drug load is (500/sh) mg/cm3. Generally, the value of sh will be about 20 cm3. The volume after lyophilization may be greater than 20 cm3 due to the expansion, or the volume after lyophilization may be less than 20 cm3 due to the collapse.
When the drug load of the lyophilized formulation packaged in a certain unit package is determined, the total external volume sh mentioned above is initially measured and calculated, and then all the lyophilized formulation packaged in the unit package is directly dissolved and the mass M of the drug contained therein is measured; and thus the drug load (per unit volume) of the lyophilized formulation of the present invention=M/sh.
Here, the mass percentage of the compound of formula I in the lyophilized formulation is greater than or equal to 40.39% and less than 66.66%. It can be converted based on the API content, and contents of excipients, and residual tert-butanol and water in the lyophilized formulation.
The mass content of the compound of formula I in a lyophilized formulation refers to the percentage of the drug relative to the total mass of the lyophilized formulation. It can be measured and calculated according to the following operations:
When measuring the drug mass content of the lyophilized formulation packaged in a certain unit package, the mass M1 of the lyophilized formulation in the unit package is initially weighed, and then the all the lyophilized formulations in the unit package is directly dissolved and the mass M of the drug contained therein is measured. When a total mass of the empty vial and packaging cap that have been cleaned, oven dried and weighed after dissolution is taken as M2, the total mass of the lyophilized formulation is M1-M2, then the mass content of the compound of formula I in the lyophilized formulation according to the present invention=M/(M1-M2).
In the above-mentioned lyophilized formulation, the compound of formula I is selected from
preferably TH-302.
The excipient is selected from saccharides, polyols, polyvinylpyrrolidones, proteins, poloxamer or a combination thereof;
After the solution has been lyophilized, water and tert-butanol as the solvent will be sublimated.
Thus, the lyophilized formulation only contains the remaining drug and excipients.
Apparently, since it is impossible to completely remove water and tert-butanol during the sublimation process of lyophilization, the residues of water and tert-butanol are inevitably included. In fact, the residual amount of water and tert-butanol is an important quality index for the lyophilized formulation: the lower the residual amount, the better the quality and stability of the lyophilized formulation will be, and after administration with such a formulation, a patient will experience less adverse reactions. Minimizing the residual amount can be fulfilled by adjusting the lyophilization process. However, residues cannot be completely avoided.
Nonetheless, by prolonging the lyophilization time and elevating the drying temperature, it is technically feasible to reduce the content of water and tert-butanol to be lower than the detection limit regardless of costs while complying with the product quality requirements. In this case, the lyophilized formulation can be considered as being almost free of water and tert-butanol.
Considering the production cost and storage stability, there are appropriate residual contents for water and tert-butanol respectively as follows: the residual water content is less than or equal to 6% by mass, preferably less than or equal to 2%, more preferably less than or equal to 1%, and further preferably less than or equal to 0.5%; and the residual tert-butanol content is less than or equal to 1.75% by mass, preferably less than or equal to 1%, and more preferably less than or equal to 0.5%.
Of course, buffers, pH regulators or other auxiliary materials for the lyophilized formulations can also be added according to the above illustrations and in combination with the properties of the specific compound of formula I. Correspondingly, the lyophilized formulations will also be detected to contain buffers, pH regulators or other adjuvants for lyophilization.
Apparently, if other substances (environmental substances), which cannot be removed by sublimation, are detected due to contact with or contamination of containers, pipes, and tools, they do not belong to the category of such auxiliary materials. Similarly, tert-butanol, sucrose, and raw materials of the compound of formula I are inevitably doped with impurities or other substances involved in the environment (environmental substances) that cannot be removed by sublimation. These impurities or environmental substances are also not included in said category of auxiliary materials.
The contents of all the other substances (environmental substances) that cannot be removed by sublimation and are detected due to contact with or contamination of containers, pipes, and tools, and impurities or other substances involved in the environment (environmental substances) that cannot be removed by sublimation inevitably doped in tert-butanol, sucrose/mannitol, and the raw materials of the compound of formula I should be within the statutory limits or comply with quality standards (pharmaceutical grade, medical grade or equivalent quality standards) of the corresponding products.
“Comprising/comprise the compound of the following formula I and excipients” means that in addition to the inevitable, residual water and tert-butanol, the lyophilized formulation can be detected to contain the compound of formula I, excipients and the above-mentioned residual environmental substances. In addition, it can also contain other adjuvants.
The mass ratio of the compound of formula I to the excipient is in the range of 1: (0.5-20), preferably in the range of 1: (1-15), more preferably in the range of 1: (2-12.5), and further preferably in the range of 1:(5-10).
The drug load of the compound of formula I in the lyophilized formulation is greater than or equal to 5.55 mg/cm3 and less than or equal to 177.77 mg/cm3, preferably greater than or equal to 8.88 mg/cm3 and less than or equal to 55.55 mg/cm3, more preferably greater than or equal to 8.88 mg/cm3 and less than or equal to 27.77 mg/cm3, more preferably greater than or equal to 8.88 mg/cm3 and less than or equal to 16.66 mg/cm3, and further more preferably greater than or equal to 8.88 mg/cm3 and less than or equal to 11.11 mg/cm3; or
the drug load of the compound of formula I in the lyophilized formulation is greater than or equal to 4.55 mg/cm3 and less than or equal to 145.45 mg/cm3, preferably greater than or equal to 7.27 mg/cm3 and less than or equal to 45.45 mg/cm3, more preferably greater than or equal to 7.27 mg/cm3 and less than or equal to 22.73 mg/cm3, more preferably greater than or equal to 7.27 mg/cm3 and less than or equal to 13.64 mg/cm3, and further more preferably greater than or equal to 7.27 mg/cm3 and less than or equal to 9.09 mg/cm3.
For the above two situations mentioned here, the former refers to the situation where the volume becomes smaller after lyophilization due to the collapse, and the latter is the situation where the volume becomes larger due to the expansion.
A lyophilized formulation is essentially consisting of the compound of the following formula I-1, an excipient, residual water and residual tert-butanol,
A lyophilized formulation is essentially consisting of the compound of the following formula I-1, an excipient, residual water, residual tert-butanol and a pH regulator,
A lyophilized formulation is essentially consisting of the compound of the following formula and an excipient,
Apparently, if other substances (environmental substances), which cannot be removed by sublimation are detected due to contact with or contamination of containers, pipes, and tools during the preparation of the solution, they do not belong to the category of such auxiliary materials. Similarly, tert-butanol, sucrose, and raw materials of the compound of formula I are inevitably doped with impurities or other substances involved in the environment (environmental substances) that cannot be removed by sublimation. These impurities or environmental substances are also not included in said category of auxiliary materials.
The contents of all the other substances (environmental substances), which cannot be removed by sublimation and are detected due to contact with or contamination of containers, pipes, and tools, and the impurities or other substances involved in the environment (environmental substances) that cannot be removed by sublimation inevitably doped in tert-butanol, sucrose/mannitol, and the raw materials of the compound of formula I should be within the statutory limits or comply with quality standards (pharmaceutical grade, medical grade or equivalent quality standards) of the corresponding products.
“Comprising/comprise the compound of the following formula I and excipients” means that in addition to the inevitable, residual water and tert-butanol, the lyophilized formulation can be detected to contain the compound of formula I, excipients and the above-mentioned residual environmental substances. In addition, it can also contain other adjuvants.
“Essentially consisting of the compound of the following formula I and excipients” means that in addition to the inevitable, residual water and tert-butanol, the lyophilized formulation can be detected to only contain the compound of formula I, excipients and the above-mentioned residual environmental substances. Apart from such components, it is free of other substances.
The present invention provides a lyophilized formulation, which is prepared through a lyophilization process by using the above-mentioned solutions for preparing a lyophilized formulation with a high drug load.
The pharmaceutical formulation and the lyophilized powders thereof can be stored in containers commonly used in the pharmaceutical field, which may include: plastic containers or glass containers, such as standard USPI type borosilicate glass containers. For example, the container to be used may be a syringe or a vial.
According to the dosages of the compound of formula I used in the animal model experiments and clinical trials described in the background art portion of this application, it can be known that the dosage of the compound to be administered each time may vary when used in different species (human beings and other animals), or against different indications, or in different patients, and it may range from the minimal amount of a few milligrams to the maximum amount of tens of thousands of milligrams. It is most preferable that a unit dose package or a combination of multiple unit dose packages can meet the dosage for a certain administration. Therefore, in view of the above, we have given recommendations for suitable dosages of the lyophilized formulation per unit package for different species or against different indications.
The present invention also provides a formulation unit package containing said lyophilized formulation:
These small doses are appropriate for juveniles among human beings or animals of comparable size, such as pigs, rats, and dogs, or other animals of small size and low weight. The indications are not limited.
The lyophilized formulation provided by the present invention is recommended to be administered by intravenous infusion. Therefore, the drug solution needs to be reconstituted. Physiological saline (0.9%) or glucose injection (5%) is generally selected for reconstitution. For this purpose, the present invention provides an injection for intravenous injection containing TH-302, wherein the solvent is water; the solute comprises the active pharmaceutical ingredient TH-302, an isoosmotic adjusting reagent, mannitol or sucrose, tert-butanol and sodium bicarbonate; and the isoosmotic adjusting reagent is selected from glucose and sodium chloride.
The present invention also provides a method for preparing a solution of the lyophilized formulation with a high drug load, comprising the following procedures:
The present invention herein provides a process for preparing the lyophilized formulation.
The method for preparing the lyophilized formulation with a high drug load comprises the following procedures:
As can be seen from the above illustrations, the lyophilized formulation was obtained by directly filling the solution into a lyophilized bottle (vial) and directly lyophilizing it in a lyophilizing device. Therefore, there is no step of sub-packaging. Accordingly, the unit package is exactly the corresponding lyophilized bottle package. The packaged gauge is closely related to the gauge of the lyophilized vial.
In particular, the numbers recited in this application may have an error of 10%. That is, the recited number being pulsed or subtracted 10% of that recited number should be considered to be within the range of the number recorded in this application. In other words, if the present application recites phrases, e.g., “the content is greater than 5 mg/ml but less than or equal to 500 mg/ml”, the actually measured content range being greater than 4.5 mg/ml and less than or equal to 550 mg/ml should also be determined as a matter of course to be equivalent to the above range.
The present invention will be described below with reference to specific examples. Those skilled in the art could understand that these examples are only used for describing the invention and do not in any way limit its scope.
“Patient” and “individual” are used interchangeably and refer to a mammal in need of treatment for cancer. Generally, the patient is a human. Generally, the patient is a human diagnosed with cancer. In certain embodiments, a “patient” or “individual” may refer to a non-human mammal used in screening, characterizing, and evaluating drugs and therapies, such as, a non-human primate, a dog, cat, rabbit, pig, mouse or rat.
“Prodrug” refers to a compound that, after administration or application, is converted to a biologically active or more active compound (or drug) with respect to at least one property by metabolism or in other ways. A prodrug is modified chemically in a way such that it has less active or inactive relative to the drug, but the chemical modification is such that the corresponding drug is produced from the prodrug by metabolic or other biological processes after the prodrug is administered. A prodrug may have, relative to the active drug, altered metabolic stability or transport characteristics, fewer side effects or lower toxicity, or improved flavor. A prodrug may be synthesized using reactants other than the corresponding drug.
“Treatment” or “treatment of a patient” means administering, using or applying a therapeutically effective amount of the drug associated with the present invention to a patient.
“Administering”, “applying” or “using” a drug to a patient refers to direct administration or application, which may be administered or applied to a patient by a medical professional or may be self-administered or applied; and/or indirect administration or application, which may be an act of prescribing a drug. For example, a physician that instructs a patient to self-administer or apply a drug or provides a patient with a prescription for a drug is administering or applying the drug to the patient.
“Therapeutically effective amount” of a drug refers to an amount of a drug that, when administered or applied to a patient with cancer, will have the intended therapeutic effect, e.g., alleviation, amelioration, palliation or elimination of one or more manifestations of cancer in the patient. A therapeutic effect does not necessarily occur by administration of one dose, and may occur only after administration of a series of doses. Thus, a therapeutically effective amount of a drug may be administered or applied one or more times.
“Treatment” of a condition or patient refers to taking steps to obtain beneficial or desired results (including clinical results). For purposes of this invention, beneficial or desired clinical results include, but are not limited to, alleviation or improvement of one or more symptoms of cancer; reduction in the severity of disease; delay or slowing of disease progression; improvement, alleviation, or stabilization of the disease state; or other beneficial results. Treatment of cancer may, in some cases, result in partial response or stable disease.
“Tumor cells” refers to tumor cells of any appropriate species, e.g., mammalian such as murine, canine, feline, equine or human.
The above description of embodiments of the present invention does not limit the present invention. Those skilled in the art can make various modifications and changes according to the present invention, and any modification and change without departing from the spirit of the present invention shall be covered in the scope of the claims appended to the present invention.
If not otherwise specified, for each of the following experiments, the measuring or inspection methods, instruments and other information are listed as follows:
Moisture content was measured by the Karl Fischer KF method using a Mettler V10S Karl Fischer moisture meter.
The content of the residual solvent tert-butanol was measured using gas chromatography (GC). The instrument used was an Agilent 8860 gas chromatograph equipped with a 7696A automatic headspace sampler and FID detector. The chromatographic column was a capillary column packed with DB-624. GC test parameters are: a carrier gas of N2; an inlet temperature of 150° C.; a detector temperature of 200° C.; a split ratio of 20:1; a temperature-elevating program with a starting temperature of 60° C., holding of the temperature for 5 minutes, elevating the temperature to 240° C. at a rate of 30° C./min, then running for 5 minutes at 60° C.; and headspace balancing at 85° C. for 20 minutes;
The content and concentration of TH-302 were measured using high-performance liquid chromatography (HPLC). The instrument used was Thermo Vanquish high-performance liquid chromatography. The chromatographic column was: YMC packAQ C18 4.6 mm×250 mm, 5 μm. For the detection method, please refer to the HPLC method described in the patent WO2008083101A1 owned by Threshold Pharmaceuticals Inc. (see Example 2. An Ethanol Formulation of TH302, for details).
If not otherwise specified, the symbol “/” included in the tables means not detected.
The solubility is measured in an experiment by the saturated solution method; that is, the solid TH-302 was directly charged into the solvent until insoluble matter or turbidity appears. After clarification for a period of time, the solution was directly filtered. The clarified filtrate was taken directly for determination of the concentration of TH-302. The resulting concentration is exactly the solubility of TH-302 in this solvent system. Please refer to Tables 1, 2, and 3 for specific solubility data.
For the method for measuring the concentration of TH-302 (mg/ml), please refer to the HPLC method described in the patent WO2008083101A1 owned by Threshold Pharmaceuticals Inc. (see Example 2. An Ethanol Formulation of TH302, for details); and the external standard method was used for quantification.
If the concentration is too high, the corresponding clear solution should be initially diluted to such an extent that HPLC can accurately measure it quantitatively.
When the mass ratio of tert-butanol in the data shown in Table 3 was taken as the X-axis, and the solubility of TH-302 in the tert-butanol-water mixed solvent as the Y-axis, the relationship curve shown in
In order to explore the feasibility of using commonly used saccharides, polyols, nonionic polymer surfactants, etc. as excipients for lyophilizing the TH-302 drug, the following excipients were selected for lyophilization experiments to investigate their stability.
Sucrose, lactose, maltose, fructose, and trehalose were selected as the saccharides.
Mannitol, glycerol and sorbitol were selected as polyols.
PVPK12 (polyvinylpyrrolidone with a molecular weight of 5500), PEG2000 (polyethylene glycol 2000), P188 (poloxamer, a polyoxyethylene polyoxypropylene ether block copolymer, brand number: 188) were selected as the nonionic polymer surfactant.
Others: SBECD (sulfobutyl ether-β-cyclodextrin), and DSPE-MPEG2000 (phosphatidylethanolamine pegol).
The drug solution for lyophilization was formulated according to Table 4 below.
※The solvent used in the experimental groups with PEG2000 and P188 protective agent is 40% TBA/water.
The TH-302 active pharmaceutical ingredient and lyo-protectant were weighed according to the above-mentioned formulation, added with the prescribed amount of tert-butanol solution, mixed homogeneously until completely dissolved, and then subpackaged (into 5 ml vials, each vial being charged with 1 ml of the drug solution, 8 vials for each formulation), and rapidly lyophilized in a small fast lyophilizer: the subpackaged formulations were pre-lyophilized at −80° C. in a ultra-low temperature refrigerator for about 2.5 hours, and then placed in a lyophilizer for about 10-90 hours (-30° C., absolute air pressure: 0.1 mbar) to obtain a lyophilized formulation.
Lyophilized powder state: white lyophilized powder cakes were successfully obtained in all the solvent groups except for those with water as the solvent. However, an oily substance appeared in the glycerol group when the lyophilizer was heated up to 0° C.
Reconstitution status: for all the groups except for the sorbitol groups, reconstitution was successful (for part of them, dissolved after being shaken).
The remaining sucrose, mannitol, lactose, maltose, fructose, PVPK12, trehalose, DSPE-MPEG2000, SBECD, PEG2000, and P188 groups were subjected to high-temperature accelerated stability experiments.
After the lyophilized formulations had been removed from the lyophilizer, one of the vials was taken out at 0° C. for testing the purity by HPLC, the moisture content and the content of the residual solvents of the active pharmaceutical ingredient. The vial was then placed in a thermostat at 40° C. The purity by HPLC was tested on day 3 and day 5, respectively. The results were shown in Table 5 below.
ND: Not detected
The curve of
Generally speaking, the selection of a lyoprotectant for injection should take into account the following factors: good stability; can be conventionally used; and will not affect the drug efficacy, DMPK, and toxicology. By analyzing the curve in
In order to further evaluate the stability of mannitol and sucrose, the purity by HPLC was tested after the mannitol and sucrose samples had been stored for 10 days, and the results were plotted into a curve, as shown in
By analyzing the curve of
3. Experiments for Investigating the Effects of Different Lyo-Protectants (100 mg/ml Sucrose or 80 mg/ml Mannitol) on the Stability of the Lyophilized Powder and the Reconstituted Solution
Based on their experiences and the use of similar lyophilized formulation drugs, the inventors have initially determined to use 100 mg/ml sucrose and 80 mg/ml mannitol as excipients to investigate the stability of the prepared lyophilized formulation of TH-302 and the stability of the reconstituted solution.
The drug solution for lyophilization was formulated according to Table 6 below. 40 vials for each group were prepared, 1 ml/vial; and a total of 40 ml drug solution was prepared for each formulation.
1. The prescribed amount of lyo-protectant was initially dissolved in the prescribed amount of water until it was completely dissolved.
2. The prescribed amount of tert-butanol was added into the aqueous lyo-protectant solution and mixed homogeneously. Then the prescribed amount of API was added and stirred until it was completely dissolved.
3. The pH of the drug solution formulated with sucrose was measured to be 4.24, and it was adjusted with 10 μL of NaHCO3 injection to 6.43. Another 10 μL of the injection was added to adjust the pH to 7.13.
The pH of the drug solution formulated with mannitol was measured to be 4.62, and it was adjusted with 12 μL of NaHCO3 injection to 7.31.
The resulting solution was filtered with PVDF and subpackaged in 1 ml/vial.
An operation similar to the aforementioned “fast lyophilization” was used and the relevant parameters were adjusted to obtain a lyophilized formulation.
After lyophilization, the vials were stoppered under vacuum and crimp-capped. The lyophilized formulation was obtained. The residual solvent and moisture in the lyophilized formulation were measured.
The lyophilized formulation samples were placed in a thermostat at 25° C. or 40° C., and the purity by HPLC was measured on the corresponding days. The results were shown in Table 7 below.
The stability curves with 100 mg/ml sucrose and 80 mg/ml mannitol were plotted using the purity by HPLC in Table 7 as the Y-axis and time as the X-axis, and were shown in
By analyzing and comparing the data shown in Table 7 and
One vial of the lyophilized powder was taken and dissolved with D5W (dextrose 5% by mass in water) to obtain a solution containing about 5 mg of API per 1 mL. Then, the obtained solution was left to stand at room temperature. The color and clarity of the solution were determined at 0, 6, and 24 hours, respectively. The results showed that a colorless, transparent, and clear solution was observed in all of the cases.
The solution was diluted with 30% acetonitrile in water at 0, 6, and 24 hours respectively to a solution containing about 1 mg of API per 1 mL, which was measured for purity by HPLC. The results were shown in Table 8 below.
One vial of the lyophilized powder was taken and dissolved with D5W to obtain a solution containing about 5 mg of API per 1 mL. The pH value and osmotic pressure of the obtained solution were measured. The results were shown in Table 9 below. During the measurement, the pH value and osmotic pressure of 5% dextrose injection were also measured.
After comparison, it was found that in terms of the stability and combination of the reconstituted lyophilized formulations, there is not much difference between the results of the formulation with the 100 mg/ml sucrose and formulation with 80 mg/ml mannitol. Both of them can meet the requirements.
By comprehensively considering the storage stability experiments of lyophilized formulations at room temperature and under high temperature acceleration and the stability and combination experiments of reconstituted lyophilized formulations, it can be seen that, under the existing rapid lyophilizing process conditions, the lyophilized formulation samples prepared using a drug solution containing mannitol as an excipient had better stability at 25° C. and 40° C. than those formulated with sucrose, while the stability and combination of the reconstituted with 5% dextrose injection was only slightly different.
The drug solution for lyophilization was formulated according to Table 10 below.
The density of tert-butanol is p=0.785 g/ml. Thus, the 40% volume ratio of tert-butanol in 200 ml of the drug solution corresponds to tert-butanol volume of 80 ml and tert-butanol mass of 62.80 g.
1. The prescribed amount of lyo-protectant was initially dissolved in an amount, which is about 80% of the prescribed amount, of water under stirring until it was completely dissolved.
2. The prescribed amount of API was added to tert-butanol and the remaining water, and dissolved under stirring.
3. The solutions obtained from the above two steps were mixed homogeneously.
4. The mixed solution was filtered. The pH values of the solutions for 01 and 02 batches were not adjusted, while the pH values of the solutions for 03 and 04 batches were adjusted to 7.0.
5. Filling: for batch 01, filled with 14 mL; for batch 02, filled with 10.5 mL; for batch 03, filled with 14 mL; and for batch 04, filled with 10.5 mL. The gauge of the filling vial is 50 mL.
One vial from each of the batches 01, 02, 03, and 04 was placed in a medical-grade refrigerator (2-8° C.), and observed for crystallization phenomenon: it was found that they all exhibited varying degrees of crystallization, as shown in
The above-mentioned filled formulations were lyophilized in a vacuum lyophilizer. The lyophilizing conditions, which were optimized in multiple times, were used, and were shown in Table 12 below. After lyophilization, the vials were stoppered under vacuum and then crimp-capped. The lyophilized formulations as shown in
The above lyophilized formulations were reconstituted with 40 ml and 50 ml of 5% dextrose solution, respectively. Results were shown in Table 13 below.
The photographs of the formulations reconstituted with 40 ml of 5% dextrose solution were shown in
The photographs of the formulations reconstituted with 50 ml of 5% dextrose solution were shown in
By comparing the experimental results, the inventors have found that although the solubility of API (TH-302) in the tert-butanol-water mixed solvent system can be up to 160 mg/ml or more, the concentration of API should be within a suitable range because:
First, an excessively high concentration of API may cause crystallization and stratification for the drug solution during the cooling procedure of the lyophilizing process, thereby affecting the lyophilizing process;
Second, an excessively high concentration of the drug may affect the reconstitution, leading to the failure of reconstitution.
Thus, there is a suitable range of API concentration. After extensive experimentation, the inventors have found that the range of 5-160 mg/ml is preferably suitable, or further the API concentration of 8-50 mg/ml may result in a stable drug solution and good quality of the subsequently lyophilized formulation.
The effects of API concentration, lyo-protectant concentration, and tert-butanol concentration on the residual solvent of the lyophilized powder were investigated, and a blank lyophilized powder was formulated and used as a control.
The drug solution for lyophilization was prepared according to Table 14 below. 10 Vials for each batch, 1 mL/vial, 10 mL in total.
1. The prescribed amount of lyo-protectant was initially dissolved in the prescribed amount of water until it was completely dissolved.
2. For batches 01, 02, 03 and 04, the prescribed amount of tert-butanol was added into the aqueous lyo-protectant solution and mixed homogeneously. Then the prescribed amount of API was added and stirred until it was completely dissolved.
For batch 05, no tert-butanol was added. The prescribed amount of API was added and stirred until it was completely dissolved.
For batches 06 and 07, the prescribed amount of tert-butanol was added into the aqueous lyo-protectant solution and mixed homogeneously. They were not added with API and were used as blank controls.
3. In this experiment, the pH was not adjusted, and the solution was subpackaged into 1 ml/vial.
The above-mentioned subpackaged formulations were pre-lyophilized in a refrigerator at −70° C. for 3 hours, and then dried in a lyophilizer for 62 hours. After lyophilization, the vials were stoppered under vacuum and then crimp-capped. The lyophilized formulation as shown in
The formulation was injected with D5W for reconstitution. For all batches to 07, the reconstitution was easy and the solutions were clear.
The lyophilized formulation samples were placed in a thermostat at 40° C., and the purity by HPLC was measured on the corresponding days. The results were shown in Table 15 below.
The tert-butanol (2 vials) and moisture (1 vial) contents of the samples on day 0 were also measured.
The results were shown in Tables 16 and 17 below.
Note: For batch 05, TBA was not added. “01 middle” and “01 lower” represent the lyophilized formulation samples obtained by lyophilizing the drug solutions, which were from the same batch and placed on different plates (middle and lower layers) in the lyophilizer.
In the samples prepared by the small lyophilizer, the TBA residues in the samples in each vial were at varying levels, and the residual TBA contents in those formulated with sucrose were higher than those formulated with mannitol.
Under the condition of 40° C., the amount of related substances in those formulated with sucrose increased largely, while the amount of the related substances in those formulated with mannitol increased slightly.
The API concentration does not have much relationship with the residual solvent content in the lyophilized formulation. Likewise, the lyo-protectant concentration does not have much relationship with the residual solvent content in the lyophilized formulation.
The API concentration, lyo-protectant concentration, and tert-butanol concentration all affect the residual solvent content in the lyophilized formulation: in comparison, the lyophilized formulation obtained by using mannitol as a lyo-excipient (lyo-protectant) has low residual level, and in stability experiments accelerated at high temperature, the formulations formulated with mannitol have better stability than those formulated with sucrose.
6.1 Investigating the Effects of Different pH Values and Filled Amounts of the Formulations (40% Tert-Butanol+60 mg/ml Mannitol+10 mg/ml API) on Sample Reconstitution
A 600 ml drug solution was prepared according to Table 18.
Density of tert-butanol is p=0.785 g/ml; thus, the volume of 240 ml corresponds to 188.4 g.
1. The prescribed amount of tert-butanol was added under stirring to the aqueous lyo-protectant solution and mixed homogeneously. Then the prescribed amount of API was added and dissolved under stirring.
2. Filtered using a sterile filter cup. Batch 01: 300 ml, no pH adjustment; Batch 02: pH 4.58, which was adjusted to 7.07; at the same time, 6 ml of solution for each batch was taken and stored in a refrigerator (2˜8° C.) to observe the crystallization phenomenon.
3. Filling:
A 600 ml drug solution was prepared according to Table 19.
Density of tert-butanol is p=0.785 g/ml, then the corresponding mass of tert-butanol in 180 ml is 141.3 g.
1. The prescribed amount of lyo-protectant was initially dissolved in about prescribed amount of water under stirring at 500 rpm until it was completely dissolved.
2. The prescribed amount of tert-butanol was added to the aqueous lyo-protectant solution and mixed homogeneously. Then the prescribed amount of API was added and dissolved under stirring.
3. Filtered using a sterile filter cup. Batch 03: 300 ml, no pH adjustment; Batch 04: pH 4.61, which was adjusted to 7.01; at the same time, 6 ml of the solution for each batch was taken and stored in a refrigerator (2˜8° C.) to observe the crystallization phenomenon;
4. Filling:
The above-mentioned subpackaged formulations were lyophilized in a vacuum lyophilizer. The lyophilization was performed using the parameters listed in Table 12. After lyophilization, the vials were stopperd under vacuum and then crimp-capped. The lyophilized formulations were obtained.
6 ml of the solutions from batches 01 and 02 were taken and stored in a refrigerator (2-8° C.) for a period of time (2 hours). Then, the solutions was clear and no crystallization was observed.
6 ml of the solutions from batches 03 and 04 were taken and stored in a refrigerator (2-8° C.) for a period of time (2 hours). Then, crystallization was observed.
All the lyophilized formulations were white cakey solids.
The solvents used for reconstituting the samples and the phenomena after reconstitution were shown in Table 20 below.
Normal pressure means the condition under which purified water was injected into a vial containing the lyophilized formulation for reconstitution when it is in communication with the external environment after the aluminum cap and rubber stopper of the vial has been opened; and normal pressure being not indicated means the condition under which purified water was directly injected into the vial containing the lyophilized formulation via a syringe (in this case, the air pressure inside the vial is lower than the external atmospheric pressure) for reconstitution.
Samples from batch 04 (8.5 ml, 13 ml, and 17 ml) were taken after being stored at 40° C. for 10 days and then reconstituted. The results were shown in Table 21 below.
Brief summary of the experiments: Storage at 40° C. for 10 days for samples from batch 04 (8.5 ml, 13 ml, and 17 ml) does not affect reconstitution. The phenomena after reconstitution for the samples do not have much difference with those for the day-0 samples.
Generally speaking, for containers with a fixed volume, it will be easier to reconstitute the lyophilized formulation obtained from the drug solution filleded in a smaller volume within certain range.
Regarding whether the pH value of the drug solution should be adjusted, relatively, the lyophilized formulations obtained by adjusting the pH value to about 7 have a better reconstitution performance.
By specific comparison, it can be found that the lyophilized formulations obtained with lower API concentration and lower mannitol content were easier to reconstitute. This suggested that simply increasing the API concentration and mannitol dosage to increase the drug load of the lyophilized formulation will result in difficult reconstitution. Suitable API concentration and mannitol content must be selected to obtain a lyophilized drug solution with a higher drug load that is easy for reconstitution.
The effects of pH on sample stability were investigated.
The drug solutions were prepared according to the scheme shown in Table 22 below. A total volume of 6500 ml was prepared. Each vial was filled with 25 mL, and 260 vials were filled in total.
Density of tert-butanol is p=0.785 g/ml, and then the mass of tert-butanol in 1950 ml is 1530.75 g. The purity of API is 99.26%.
{circle around (1)} Preparation of 70% tert-butanol aqueous solution: the solution was obtained by weighing 350.81 g of tert-butanol and 150.42 g of water.
{circle around (2)} Pre-dissolution: the prescribed amount of API was weighed; API was added to 70% tert-butanol aqueous solution under stirring conditions and dissolved under stirring. The resulting solution was recorded as Solution A.
{circle around (3)} Under stirring conditions, the prescribed amount of mannitol was initially dissolved in 70% of the remaining water. The resulting solution was stirred until it was clear and recorded as Solution B.
{circle around (4)} Solutions A and B were mixed and stirred homogeneously. Then the mixed solution was added with the remaining water and remaining tert-butanol after being used to rinse; the pH of the obtained intermediate drug solution was 5.63.
{circle around (5)} The drug solution was divided into 3 equal portions.
Drug solution-01: pH was not adjusted; and the pH was measured to be 4.77 after storage at room temperature for 24 hours.
Drug solution-02: 200 μl of sodium bicarbonate was added, and the pH was measured to be 6.60 (pH between 6.0 and 6.5). The pH was measured to be 5.20 after storage at room temperature for 24 hours.
Drug solution-03: 1000 μl of sodium bicarbonate was added, and the pH was measured to be 7.20 (pH at 7.0). The pH was measured to be 6.90 after storage at room temperature for 24 hours. The intermediate drug solution at 0 hour and the drug solution after storage at room temperature for 24 hours were taken respectively, and measured for their contents and related substances.
The solutions were filtered using a 250 ml sterile filter cup.
For Drug solution—01 batch, filled with 24.5 g to give 78 vials, and recorded as Batch 01.
For Drug solution—02 batch, filled with 24.5 g to give 78 vials, and recorded as Batch 02.
For Drug solution—03 batch, filled with 24.5 g to give 78 vials, and recorded as Batch 03.
After package, the vial was half-stoppered and placed in a lyophilizer for freeze-drying.
The above-mentioned subpackaged formulations were lyophilized in a vacuum lyophilizer. The arrangement sequence of the vials in this lyophilizer model was shown in
The test results of the drug solutions were shown in Table 23.
The state of the lyophilized formulation sample: white cakey solid; the specific samples were shown in
Lyophilized formulations from different batches and locations were taken and reconstituted, respectively. The results were shown in Table 24 below.
Note: the reconstituted solution of batch 02 (blank powder) was as clear as water; and reconstituted solutions of batch 01, batch 02, and batch 03 were slightly more turbid than water.
In order to further investigate the reconstitution effect with the commonly used intravenous infusion solution—physiological saline, after being reconstituted with purified water to an API concentration of about 5 mg/ml, the formulation was further diluted with physiological saline to 0.5 mg/ml (5 ml was taken out to be added to 50 ml sodium chloride injection, 0.5 mg/ml): clear solutions were obtained, and then the pH value and osmotic pressure data were measured. The results were shown in Table 25 below.
Samples were taken at different time periods after reconstitution with physiological saline to measure the purity of the API by HPLC in the solution. The results were shown in Table 26 below.
The lyophilized formulation samples were placed in a thermostat at 40° C., 25° C., and 2-8° C., and the purities were measured by HPLC on the corresponding days. The results were shown in Table 27 below.
The tert-butanol (2 vials) and moisture (2 vials) contents of the 0-day samples of batch 01, batch 02, and batch 03 were measured, respectively. Note that samples from the middle of the freeze-drying machine plate were taken. The results are shown in Table 28 below.
8. Preparation Examples of Formulation Lyophilized with the Solutions with Different Tert-Butanol Concentrations, Different Excipients (Sucrose or Mannitol), Different Excipient Amounts, Different Drug Contents, and Different pH Values after Lyophilization
Considering that the quality indicators of lyophilized formulations include three main investigative indicators: reconstitution, stability, and residual solvent, and it can be found from the above experiments that the influencing factors include solvent (volume ratio of tert-butanol in the tert-butanol-water mixed solvent), API concentration, type (mannitol or sucrose) and amount of excipients, and pH value of the drug solution, the inventors have conducted several multi-factor experiments. The results were shown in Table 28 below.
“30% TBA/70Mannitol/10API-pH7.0” in the formulation means 30% volume ratio of tert-butanol, 70 mg/ml of mannitol, 10 mg/ml of API, and 7.0 of pH adjusted by adding NaHCO3. The preparation method was the same as those mentioned in the above examples. “40% TBA/60Mannitol/10API” means 40% volume ratio of tert-butanol, 60 mg/ml of mannitol, 10 mg/ml of API, without pH adjustment (weak acidity), and so on for the rest.
50 ml vials were used except for 5 ml vials used for the batch with a deliverable volume of 1 ml.
1. From the solubility data of TH-302 in the tert-butanol-water mixed solvent system in combination with the above-mentioned experiments and the 85 groups of exploratory experimental results shown in Table 28 above, it can be estimated or validated that the compound can be stably present in the solution when its content is ranging from 5-500 mg/ml; and the experiments have demonstrated that lyophilization is possible when the content is greater than 8 mg/ml and less than or equal to 200 mg/ml, though the lyophilizing parameters may need to be adjusted, e.g., being pre-lyophilized at −80° C., being lyophilized at much lower absolute air pressure, longer drying duration, and lower drying temperature. Preferably, when the content of the compound of formula I in the solution is greater than or equal to 8 mg/ml and less than or equal to 25 mg/ml, the lyophilized formulation has better stability and is easier to reconstitute. The content of the compound of formula I in the solution is greater than or equal to 8 mg/ml and less than or equal to 15 mg/ml. Such a content range means relatively mild lyophilizing conditions and shorter lyophilizing cycle. The content of the compound of formula I in the solution being greater than or equal to 8 mg/ml and less than or equal to 10 mg/ml furthers means that the lyophilized formulation has commercial large-scale production value under commercially suitable lyophilization cycles and low-temperature conditions: unsuitable API content may lead to broken vials or spraying powders in the large-scale lyophilizer used during commercial mass production due to uneven heating temperatures, thereby resulting in a yield lower than 90% of the acceptance level for commercial production.
2. From the solubility data of TH-302 in the tert-butanol-water mixed solvent system in combination with the above experiments and the results of the 85 groups of exploratory experiments shown in Table 28 above, it can be estimated or validated that when the volume percentage of tert-butanol relative to the solution is 1-99% or the content of tert-butanol in the solution is 7.85-777.15 mg/ml (under the condition that the density of tert-butanol is 0.785 g/ml), the prepared TH-302 solution is stable and clear, and the experiments have demonstrated that lyophilization is possible when the volume ratio is 5-95% or the tert-butanol content in the solution is 39.25-745.75 mg/ml (under the condition that the tert-butanol density is 0.785 g/ml), though the lyophilizing parameters may need to be adjusted, e.g., pre-lyophilizing at −80° C., lower absolute air pressure during lyophilization, longer drying duration and lower drying temperature. Preferably, when the volume ratio of tert-butanol is 30-60% or the tert-butanol content in the solution is 235.5-471 mg/ml (under the condition that the tert-butanol density is 0.785 g/ml), the lyophilized formulation has better stability and are easier to be reconstituted.
In fact, in the tert-butanol-water mixed solvent system, excessively higher tert-butanol content will affect the subsequent dissolution of mannitol/sucrose, and after mannitol/sucrose has served as the excipient, their amounts will directly affect the quality of the subsequent lyophilized formulation: if the amount of mannitol/sucrose is too low, the drug solution will be unable to be evenly loaded onto the excipient skeletons after lyophilization, or even cause collapse of the lyophilized powder cake or failure of lyophilization during the drying stage of the lyophilizing process. Thus, the content of tert-butanol cannot be increased inappropriately merely for the purpose of increasing the solubility of TH-302.
3. According to the solubility data of TH-302 in the tert-butanol-water mixed solvent system in combination with the above experiments and the results of the 85 groups of exploratory experiments shown in Table 28 above, it can be seen that the lyophilized formulations can be obtained when mannitol, PEG2000, P188, SBECD, DSPE-MPEG2000, sucrose or other similar substances is used as the excipient. However, after comparison, it is more appropriate to use sucrose and mannitol after comprehensively considering the factors besides those of the lyophilized formulation itself, e.g., whether it could be routinely used and commercially available, and whether it will affect the efficacy, DMPK and toxicology. The lyophilized formulations prepared by using such an excipient have appropriate stability in solution (a duration of at least 24 hours at room temperature), and the lyophilized formulations are stable, could be readily reconstituted, and are easy to obtain products that meet the requirements of excipients for injection formulations.
4. In fact, just as mentioned under the above Item 2, a higher content of mannitol/sucrose as an excipient does not necessarily mean a better effect: although a higher amount of the excipient can provide lyophilized skeletons loading more drugs and is also beneficial for lyophilization production and improving the stability of lyophilized formulations, it is affected by its solubility in the tert-butanol-water mixed solvent system. Excessively higher amount of mannitol/sucrose may make the mixed solvent unable to be completely dissolved or the solution unstable, and thus precipitation may occur during the pre-lyophilizing stage or cooling stage. Thus, the amount of mannitol/sucrose used as an excipient in the lyophilized solution should also be within a suitable range to meet the above-mentioned requirements.
The content of sucrose or mannitol in the solution is 20-300 mg/ml. Such a range can meet the above requirements: the drug solution is stable and precipitation is not easy to occur during the pre-lyophilizing stage or cooling stage of the lyophilization process. Further preferably, the content is 40-100 mg/ml, and it is possible to obtain a reconstituted solution and a lyophilized formulation with good stability. More preferably, the content is 60-70 mg/ml. Such a content range means that the lyophilizing conditions are relatively mild and the lyophilizing cycle is in line with commercial production practices (less than 10 days, i.e., a 240-hour for one production cycle).
5. As mentioned in the above Item 2, excessively low amount of mannitol/sucrose will cause the drug solution to be unable to be evenly loaded on the excipient skeletons after lyophilization, or may even cause the lyophilized powder cake to collapse during the drying stage of the lyophilization process or failure of lyophilization; and although excessively high amount of mannitol/sucrose can produce a lyophilized formulation with better appearance and stability, it means that the content of the drug TH-302 in the lyophilized formulation per unit package would be too low to meet the requirements for commercial sales and usage. Thus, a suitable ratio between mannitol/sucrose and the active drug is essential. The mass ratio of the compound of formula I to the excipient in the solution is in the range of 1: (0.5-20). Such a ratio can meet the requirements as mentioned in the above Items 1-4 for the other ingredients, and can enable the prepared lyophilized formulation to have better appearance and stability; preferably the mass ratio is in the range of 1:(2-12.5), which can afford a better lyophilized formulation that is easy to reconstitute; and more preferably the mass ratio is in the range of 1:(5-10), with which the prepared lyophilized formulation will have excellent properties: having good stability of lyophilized formulations, being easy to reconstitute, having mild lyophilizing conditions and short lyophilizing cycle.
6. Experimental phenomena showed that the pH value of the drug solution for lyophilization will directly affect its stability and the complexity level of reconstitution and the stability of the corresponding lyophilized formulation. Experiments have proved that if the drug solution was not added with a pH regulator (a base or basic salt), the drug solution would be acidic, and the acidic drug solution would have poor stability, the corresponding lyophilized formulation would be reconstituted unsatisfactorily and have low stability; when a pH regulator (a base or basic salt) was added, these could be improved significantly.
7. It is worth mentioning that the filled volume of the drug solution in the vial can also affect the appearance and reconstitution of the finally lyophilized powder cake (powder being sprayed or adhered to the bottleneck of the vial) by multiple factors. Therefore, the ratio of the filled volume of the drug solution in the vial and the volume of the vial must be appropriate. After considering the above-mentioned experimental data and the actual production practice, it is appropriate that the filled volume of the lyophilized drug solution is ⅓ to ½ of the volume of the sealed container, and the volume of the corresponding lyophilized formulation is ⅓ to ½ of the volume of the sealed container.
The TH-302 sample was weighed accurately in an amount of about 60 mg, placed in a transparent vial, and added with 6 ml of dextrose 5% in water (D5W). The resulting solution was shaked vigorously for 2 minutes to obtain a solubility-stock solution. It was observed that the solubility-stock solution contained insoluble substances. Thus, the solubility-preserving solution was filtered and then became clear. The filtered filtrate was left to stand at room temperature for 24 hours, and was found to be still clear. After sampling and appropriate dilution, the content of the solution was measured by HPLC to be 7.25 mg/ml. This value was exactly the saturated solubility of the drug in D5W solution.
It can thus be seen that the concentration of TH-302 in the TH-302-containing injection for intravenous administration should be within the range of 0-7.25 mg/ml. In fact, considering the isotonicity and the osmotic pressure of the glucose contained in intravenous injection, further research is needed to determine suitable infusion formula during intravenous drip.
The drug solution in Experiment 7 was filled: 25 ml of the drug solution was filled into a 50 ml vial, and the liquid level height after the drug solution being filled was measured. The average height was 26.5 mm. After lyophilization, the heights of the lyophilized powder cake in the vials at different plate positions of the lyophilizer were measured, and the difference in volume compared with the 25 ml before filling was roughly calculated.
In the multi-batch experiments, it was found that the volumes before lyophilization in some batches were increased after lyophilization, in some batches were decreased, and in some batches remained almost unchanged. By marking the liquid levels before and after lyophilization and statistically analyzing the volume changes, it was found that the maximum amplitude of volume increment or decrease is 10%; that is, the volume change is within +10%.
In the case where the volume of the lyophilized powder cake is decreased by 10% after lyophilization:
If the content of the drug solution is 6, 7, 7.5, 8, 8.5, 10, 12.5, 15, 20, or 25 mg/ml, the corresponding drug load of the lyophilized powder cake is 6.66, 7.77, 8.33, 8.88, 9.44, 11.11, 13.88, 16.66, 22.22, or 27.77 mg/cm3.
In the case where the volume of the lyophilized powder cake is increased by 10% after lyophilization:
If the content of the drug solution is 6, 7, 7.5, 8, 8.5, 10, 12.5, 15, 20, or 25 mg/ml, the corresponding drug load of the lyophilized powder cake is 5.45, 6.36, 6.82, 7.27, 7.73, 9.09, 11.36, 13.64, 18.18, or 22.73 mg/cm3.
Since the formulation obtained by lyophilizing drug solution contains API drug, excipients, and residual tert-butanol solvent and water, and the mass ratio of the API drugs and excipients in the lyophilized formulations prepared by the applicants is in the range of 1: (0.5-20), the maximum allowable tert-butanol content is 1.75% by mass, and the water content is 6% by mass, then the lower limit of the API drugs by mass percentage in the lyophilized formulation is (1/20+1)*(1-6%-1.75%)=4.76%*92.25%=4.39%, and the upper limit is (1/0.5+1)*(1-0%-0%)=66.66%; that is, the content of the API drug in the lyophilized formulation is greater than or equal to 4.39% and less than 66.66%.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202110996128.8 | Aug 2021 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2022/115176 | 8/26/2022 | WO |
