Patent Application
20210338649
The present invention belongs to the field of medical technology, and relates to a composition injection and preparation method and non-clinical safety thereof.
Nimodipine (Nim), also known as Nimotop, is a second-generation pyridines calcium antagonist. Nimodipine injection was developed and launched by Bayer in Germany in April 1985. Now there are more than 100 manufacturers in China. Nimodipine is easy to penetrate the blood-brain barrier due to its high lipophilicity, in addition, it can selectively dilate cerebral vessels and significantly reverse the spasm of the basilar artery and anterior spinal artery. Therefore, it is clinically used to treat hypertension, stroke, migraine, subarachnoid hemorrhage, and other cerebral hemorrhage diseases. Currently, it is the preferred drug for treating cerebrovascular diseases, especially for senile dementia.
In the prior art, nimodipine preparations commonly used clinically include tablets, capsules, and injections. Nimodipine is insoluble in water, with low solubility and strong liver first-pass effect, reducing the oral bioavailability which is 5-13% and 3-28% respectively in healthy subjects and patients with subarachnoid hemorrhage. With a short biological half-life (about 1.5-2 h), frequent administration is required. i.e. 3-4 times per day, besides the inconvenience for administration, resulting in a “peak-and-valley” pattern of plasma concentration bringing toxic and side effects. Due to its insolubility in water, all nimodipine injections used clinically contain high-concentration ethanol for solubilization, which is very irritating to skin and blood vessels. Hence, nimodipine must be administered by dripping at a slow rate of 1-2 mg/h, otherwise, no patient can tolerate its side effects, that is, 10 mg dose generally requires at least 5 hours. Moreover, it must be infused into the body as a mixture with glucose or normal saline, or separately but synchronously with glucose or normal saline with a special three-way infusion set. In most cases, nimodipine injection is transferred to an infusion bottle for mixing evenly before use. Nimodipine injection is a water-insoluble preparation containing ethanol as it is soluble in ethanol but insoluble in water. When it is co-administrated with other injections, crystallization can be present, which decreases the concentration and effectiveness of the drug and endangers patients to some extent.
There are different crystalline forms for nimodipine, i.e. α and β. The solubility is different in solvents for different crystalline forms. According to published literature, the β-type has a melting point of 124-125° C. and good solubility in water (3.6 μg/mL), while the α-type has a melting point of 114-116° C. and the solubility in water of 2.5 μg/mL. The solubility in an oil phase was not reported yet. The present invention compares the solubility in oils between a kind of commercial nimodipine (β-type, Xinhua Pharmaceutical) and self-made nimodipine (α-type), and it is found that their solubility in oils is much greater than that in water. Furthermore, the solubility of α-type is much greater than that of β-type both in the medium-chain fatty oil and the mixture of soybean oil and medium-chain fatty oil (see the table below). Therefore, formulating α-type nimodipine into a fat emulsion injection may solve the problems of low drug loading efficiency, poor safety, and poor stability occurring in its solution for injection and other fat emulsions for injection developed by the prior art.
The main component(s) of emulsion injection, such as soybean oil, medium-chain fatty oil, and the mixture thereof not only act as non-toxic solvent(s), but also introduce and dissolve fat-soluble drug into the lipid core of emulsion particles, the drug is then metabolized and slowly released along with lipid droplets so as to maintain effective plasma concentration and reduce its toxic and side effects. Moreover, the emulsion injection with the composition in the present invention has many other advantages, including increased solubility of nimodipine, increased drug loading efficiency, reduced drug hydrolysis, increased stability, and reduced toxicity, showing a good clinical application prospect.
At present, there are many literatures and patent applications about nimodipine fat emulsion, but all with some shortcomings. For example, Tween 80 is used in the prescription of an issued patent in China with the application number 200910021091.6. There have been many reports of clinical adverse reactions caused by intravenous injections containing Tween 80 which can cause hemolytic reaction, acute hypersensitivity reaction, peripheral neurotoxicity, inhibition of P-gly coprotein activity and intrinsic anti-tumor effect, hepatotoxicity, etc., so intravenous injections containing Tween 80 should he used with caution. The cosolvent benzyl alcohol is used in the prescription of another issued patent in China with the application number 200510081668.4. Benzyl alcohol has the functions of disinfection, antisepsis, and local anesthesia. It is used as a bacteriostatic agent and analgesic agent in injections but with hemolysis action. Intramuscular injection for pediatrics containing benzyl alcohol may cause gluteal muscle contracture. There are strict restrictions on the use of bacteriostatic agents in intravenous injections under the section “Injections” in the Appendix to Chinese Pharmacopoeia (2015 Edition), so it is not recommended. Meanwhile, the crystalline forms are not considered for all the current nimodipine emulsions. The crystalline forms other than α-type have low solubility and poor drug loading efficiency, and tend to crystalize during storage, reducing product stability. Considering the above-mentioned problems in the stability and safety of nimodipine compositions, it is necessary to develop a new nimodipine emulsion composition to meet the clinical needs.
One of the objectives of the present invention is to provide a nimodipine injection composition which comprises the following components: nimodipine, oil for injection, emulsifier, complexing agent, stabilizer, and osmotic pressure adjusting agent.
The said injection composition comprises 0.02-0.23% of nimodipine, 2-30% of oil for injection, 0.8-3% of emulsifier, 0-0.1% of complexing agent, 0-0.3% of stabilizer, and 1-3% of osmotic pressure adjusting agent. One preferred proportion is 0.04-0.20% of nimodipine, 3-20% of oil for injection, 1-2.5% of emulsifier, 0-0.05% of complexing agent, 0-0.2% of stabilizer, and 2-3% of osmotic pressure adjusting agent. A more preferred proportion is 0.08-0.18% of nimodipine, 8-12% of oil for injection, 1-2% of emulsifier, 0-0.01% of complexing agent, 0-0.1% of stabilizer and 2-2.5% of osmotic pressure adjusting agent. The pH value of the formulated nimodipine injection composition is 6.0-8.5, preferably 6.5-8.0, and more preferably 7.0-7.5. The mean particle size of the formulated nimodipine injection compositions is 100-600 nm, preferably 120-400 nm, and more preferably 140-300 nm.
The said nimodipine is selected from α-type or β-type, preferably a-type with the melting point of 114-116° C.
The emulsifier in the said injection composition is selected from soya lecithin or egg yolk lecithin.
The soya lecithin or egg yolk lecithin in the said injection composition contains 60-90% of phosphatidylcholine (PC) and 2-20% of phosphatidyl ethanolamine (PE), preferably 70-85% for phosphatidylcholine (PC) and 5-18% for phosphatidyl ethanolamine (PE).
The complexing agent(s) in the said injection composition may be selected one or more from calcium disodium edetate, disodium edetate, sodium edetate, and edetate acid, preferable disodium edetate.
In the said injection composition, the oil for injection is selected from soybean oil for injection, or medium-chain triglyceride for injection, or the mixture thereof. The mixture of them is preferred, with a mass ratio of soybean oil for injection and medium-chain triglyceride for injection preferably at 2:8-5:5, more preferably at 4:6-5:5, and most preferably at 4:6.
In the said injection composition, the preferred stabilizer is oleic acid or sodium oleate.
In the said injection composition, the osmotic pressure adjusting agent is glycerol.
The present invention also provides a method for preparing the nimodipine injection composition. The present invention has the following advantages: the injection composition contains no solubilizer ethanol, avoiding irritation to skin and blood vessels. The emulsification and solubilization required by the nimodipine injection are achieved without adding auxiliary emulsifiers such as Tween 80 and cosolvents such as benzyl alcohol. Through the study on different ratios of soybean oil and medium-chain triglycerides and different crystalline forms of nimodipine, a method is developed to avoid the oil-water separation caused by excessive use of medium-chain triglycerides while nimodipine can be loaded to the maximum extent. Specifically, the following problems are solved:
1. The stability problem is solved. The proper selection of emulsifiers, i.e. egg yolk lecithin or soya lecithin with a certain content range of phosphatidylcholine (70-85%) and phosphatidyl ethanolamine (5-18%), solves the stability problem, without the auxiliary emulsifier Tween 80, and reducing the risks of sensitization, allergic reaction and hemolysis in clinical application.
2. Through the study on emulsifiers in oil phase and aqueous phase respectively, it is preferred to add a part of an emulsifier into oil phase and the other into aqueous phase, resulting in a better emulsifying effect, more uniform emulsion particles and more stable emulsion.
3. The problems of solubilization and frequent industrial homogenization are solved. The α-type of nimodipine with a melting point of 114-116° C. and the oil for injection with a mass ratio of soybean oil for injection and medium-chain triglyceride for injection at 4:6 are preferred, as it may maximize the drug loading efficiency and avoid oil-water separation.
4. The cosolvents such as benzyl alcohol are not required, thus avoiding adverse reactions caused by benzyl alcohol in clinical use.
5. The oil phase is easier to emulsify and disperse by the addition of medium-chain triglycerides, which can reduce the homogenization times and is more conducive to industrial production.
6. The use of complexing agent can not only achieve antioxidant effect, but also greatly reduce the anisidine value of the preparation and improve the safety of the preparation.
7. Through non-clinical safety studies on allergy, irritation, hemolysis, rats, etc., the results show that:
(1) In the passive anaphylaxis test in rats, sensitized rats showed passive cutaneous anaphylaxis reactions to nimodipine emulsion of the prior art, while sensitized rats had no such reaction to the composition injection of the present invention. In the active systemic anaphylaxis test in guinea pigs, the guinea pigs in the high-dose group of the composition injection of the present invention immediately (about 1 minute) developed prone immobility, followed by death and other similar anaphylaxis reactions, with a mortality of 100%. No significant abnormal reactions were observed in the guinea pigs in the low-dose group. However, both high- and low-dose groups of nimodipine emulsion of the prior art developed prone immobility, followed by death and other similar anaphylaxis reactions, with a mortality rate of 100% in the high dose group and 40% in the low dose group respectively.
(2) The nimodipine emulsion of the prior art had hemolysis and agglutination effects, while the composition injection of the present invention had no hemolysis and agglutination effects.
(3) The vascular irritation test in rabbits showed that both the composition injection of the present invention and the nimodipine emulsion of the prior art had no significant irritating effect on the ear veins (blood vessel) of rabbits.
(4) The muscle irritation test in rabbits showed that both the composition injection of the present invention and the nimodipine emulsion of the prior art had no significant irritation effect on quadriceps femoris of rabbits.
The zebrafish-based cardiovascular toxicity experiments showed that the injection with the composition of this invention would also induce cardiovascular toxicity, such as decreased heart rate, atrial arrest, pericardial edema, and circulatory deficiency as the other three types of nimodipine (the drug substance, solution for injection, and emulsion formulated by existing technology) did. But compared with the lower levels of maximum non-lethal concentration of other three types (2.5 μg/ml for nimodipine drug substance and nimodipine solution for injection, and 5.0 μg/ml for nimodipine emulsion by existing technology), the maximum non-lethal concentration of the injection with the invented composition was up to 10 μg/mL, which was 4 times that of the former two, and 2 times that of the latter, indicating that the toxicity induced by the injection of this invented composition in zebrafish is much less than that of nimodipine drug substance, nimodipine solution for injection, and nimodipine emulsion by existing technology.
For nimodipine solution for injection, the experimental results in rats showed that there were significant toxic and adverse effects in the high dose group, with the death of several rats during the administration. After multiple doses of the nimodipine solution for injection, several animals developed significant phlebitis and tail ulceration. However, for the injection with the composition of this invention, there were no deaths or any other observed adverse effects in neither dose group during the administration.
The technical protocol of the invention is as follows:
The nimodipine injection composition comprises the following components in parts by mass concentration: 0.02-0.23% of nimodipine, 2-30% of oil for injection, 0.8-3% of emulsifier, 0-0.1% of complexing agent, 0-0.3% of stabilizer, 1-3% of osmotic pressure adjusting agent. One preferred proportion is 0.04-0.20% of nimodipine, 3-20% of oil for injection, 1-2.5% of emulsifier, 0-0.05% of complexing agent, 0-0.2% of stabilizer, and 2-3% of osmotic pressure adjusting agent. A more preferred proportion is 0.08-0.18% of nimodipine, 8-12% of oil for injection, 1-2% of emulsifier, 0-0.01% of complexing agent, 0-0.1% of stabilizer and 2-2.5% of osmotic pressure adjusting agent. The pH value of the formulated nimodipine injection composition is 6.0-8.5, preferably 6.5-8.0, and more preferably 7.0-7.5. The mean particle size of the formulated nimodipine injection compositions is 100-600 nm, preferably 120-400 nm, and more preferably 140-300 nm.
The said nimodipine is selected from α-type or β-type, preferably α-type with the melting point of 114-116° C.
In the said nimodipine injection composition, the emulsifier(s) may be selected one or more from soya lecithin, egg yolk lecithin, hydrogenated soybean phospholipid and hydrogenated egg yolk lecithin.
In the said nimodipine injection composition, the complexing agent(s) may be selected one or more from calcium disodium edetate, disodium edetate, sodium edetate and edetate acid.
In the said nimodipine injection composition, the preferred stabilizer is oleic acid or sodium oleate.
In the said nimodipine injection composition, the osmotic pressure adjusting agent is glycerol.
The pH value of the nimodipine injection composition is 6.0-8.5, preferably 6.5-8.0, and more preferably 7.0-7.5.
The mean particle size of the nimodipine injection composition is 100-600 nm, preferably 120-400 nm, and more preferably 140-300 nm.
The present invention also discloses a method for preparing nimodipine injection composition, comprising the following steps:
(1) Take an appropriate amount of water for injection, adjust the pH value, add complexing agent and stabilizer and stir to dissolve it, then add the osmotic pressure adjusting agent, mix well to obtain the aqueous phase, and control the water temperature at 50-70° C.
The complexing agent(s) may he selected one or more from calcium disodium edetate, disodium edetate, sodium edetate and edetate acid, and the preferable complexing agent is disodium edetate. The preferred osmotic pressure adjusting agent is glycerol.
(2) Take an appropriate amount of oil for injection, add 40% of the formulated amount of emulsifier and stabilizer, shear and mix well, heat in a water bath to 50-70° C., add nimodipine and stir to dissolve it to obtain the oil phase. The said nimodipine is selected from α-type or β-type, preferably α-type with the melting point of 114-116° C.
The said oil for injection is selected from soybean oil for injection, or medium-chain triglyceride for injection, or the mixture thereof. The mixture of them is preferred, with a mass ratio of soybean oil for injection and medium-chain triglyceride preferably at 2:8-5:5, more preferably at 4:6-5:5, and most preferably at 4:6.
(3) Add sodium oleate to the aqueous phase (1) in case sodium oleate is used as the stabilizer add oleic acid to the oil phase (2) in case oleic acid is used.
(4) Add 60% of the formulated amount of emulsifier to the aqueous phase, and shear the emulsifier to disperse evenly under nitrogen protection.
The emulsifier is selected from soya lecithin or egg yolk lecithin, which has a phosphatidylcholine (PC) content of 60-90% and a phosphatidyl ethanolamine (PE) content of 2-20%. The preferable ranges of the phosphatidylcholine (PC) content and the phosphatidyl ethanolamine (PE) content in the soya lecithin or egg yolk lecithin are 70-85% and 5-18% respectively.
(5) Add the oil phase slowly to the aqueous phase and shear it into coarse emulsion.
(6) Homogenize the coarse emulsion, and circulate until the particle size of emulsion conforms to the provisions.
(7) Measure the pH value and the emulsion particle size of the sample, fill with nitrogen, and perform filling, sealing and sterilization.
The present invention is further detailed as follows in combination with examples, but is not limited to these examples:
A total of 1 g of nimodipine, 40 g of soybean oil, 60 g of medium-chain triglyceride, 12 g of egg yolk lecithin, 0.05 g of disodium edetate, 0.3 g of oleic acid, 22.5 g of glycerol, an appropriate amount of pH regulator, and water for injection to get 1000 ml. The preparation method is as follows:
(1) Take the formulated amount of water for injection, adjust the pH value with 2% sodium hydroxide solution, add disodium edetate, stir to dissolve it, then add glycerol, and mix well. Control the water temperature at 50-70° C.
(2) Take and mix the formulated amount of soybean oil and medium-chain triglyceride, add 40% of the formulated amount of egg yolk lecithin and oleic acid, shear and mix well, heat in a water bath to 50-70° C., add the formulated amount of nimodipine and stir to dissolve it.
(3) Add 60% of the formulated amount of egg yolk lecithin to the aqueous phase, and shear the emulsifier to disperse evenly under nitrogen protection.
(4) Add the oil phase slowly to the aqueous phase and shear it into coarse emulsion.
(5) Homogenize the coarse emulsion, and circulate until the particle size of emulsion conforms to the provisions.
(6) Measure the pH value and the emulsion particle size of the sample; in case the values are acceptable, filter through the filter membrane, fill with nitrogen, and perform filling and sealing.
(7) Sterilize at 121° C. for 12 min.
(8) The pH value is 7.3, and the mean particle size is 155 nm.
A total of 1.5 g of nimodipine, 40 g of soybean oil, 60 g of medium-chain triglyceride, 12 g of egg yolk lecithin, 0.05 g of disodium edetate, 0.3 g of oleic acid, 22.5 g of glycerol, an appropriate amount of pH regulator, and water for injection to get 1000 ml. The preparation method is as follows:
(1) Take the formulated amount of water for injection, adjust the pH value with 2% sodium hydroxide solution, add disodium edetate, stir to dissolve it, then add glycerol, and mix well. Control the water temperature at 50-70° C.
(2) Take and mix the formulated amount of soybean oil and medium-chain triglyceride, add 40% of the formulated amount of egg yolk lecithin and oleic acid, shear and mix well, heat in a water bath to 50-70° C., add the formulated amount of nimodipine and stir to dissolve it.
(3) Add 60% of the formulated amount of egg yolk lecithin to the aqueous phase, and shear the emulsifier to disperse evenly under nitrogen protection.
(4) Add the oil phase slowly to the aqueous phase and shear it into coarse emulsion.
(5) Homogenize the coarse emulsion, and circulate until the particle size of emulsion conforms to the provisions.
(6) Measure the pH value and the emulsion particle size of the sample; in case the values are acceptable, filter through the filter membrane, fill with nitrogen, and perform filling and sealing.
(7) Sterilize at 121° C. for 12 min.
(8) The pH value is 6.9, and the mean particle size is 162 nm.
A total of 0.2 g of nimodipine, 50 g of soybean oil, 8 g of egg yolk lecithin, 0 g of disodium edetate, 0.2 g of sodium oleate, 25 g of glycerol, an appropriate amount of pH regulator, and water for injection to get 1000 ml. The preparation method is as follows:
(1) Take the formulated amount of water for injection, adjust the pH value, add sodium oleate, stir to dissolve it, then add glycerol and mix well. Control the water temperature at 50-70° C.
(2) Take and mix the formulated amount of soybean oil and medium-chain triglyceride, heat in a water bath to 50-70° C., add 40% of the formulated amount of egg yolk lecithin, shear and mix well, add the formulated amount of nimodipine and stir to dissolve it.
(3) Add 60% of the formulated amount of egg yolk lecithin to the aqueous phase, and shear the emulsifier to disperse evenly under nitrogen protection.
(4) Add the oil phase slowly to the aqueous phase and shear it into coarse emulsion.
(5) Homogenize the coarse emulsion, and circulate until the particle size of emulsion conforms to the provisions.
(6) Measure the pH value and the mean emulsion particle size of the sample; in case the values are acceptable, filter through the filter membrane, fill with nitrogen, and perform filling and sealing.
(7) Sterilize at 121° C. for 12 min.
(8) The pH value is 7.4, and the mean particle size is 150 nm.
A total of 2.3 g of nimodipine, 80 g of soybean oil, 120 g of medium-chain triglyceride, 15 g of egg yolk lecithin, 0.1 g of disodium edetate, 1 g of oleic acid, 20 g of glycerol, an appropriate amount of pH regulator, and water for injection to get 1000 ml.
The preparation method is the same as Example 1.
The pH value is 7.2, and the mean particle size is 296 nm.
A total of 0.4 g of nimodipine, 40 g of soybean oil, 60 g of medium-chain triglyceride, 8 g of egg yolk lecithin, 0.03 g of disodium edetate, 0.3 g of oleic acid, 22.5 g of glycerol, an appropriate amount of pH regulator, and water for injection to get 1000 ml.
The preparation method is the same as Example 1.
The pH value is 7.9 and the mean particle size is 600 nm.
A total of 0.8 g of nimodipine, 30 g of soybean oil, 70 g of medium-chain triglyceride, 30 g of egg yolk lecithin, 0.0 g of disodium edetate, 0.0 g of oleic acid, 22.5 g of glycerol, an appropriate amount of pH regulator, and water for injection to get 1000 ml.
The preparation method is the same as Example 1.
The pH value is 6.8 and the mean particle size is 146 nm.
A total of 1.2 g of nimodipine, 120 g of soybean oil, 180 g of medium-chain triglyceride, 30 g of egg yolk lecithin, 0.0 g of disodium edetate, 0.3 g of oleic acid, 20 g of glycerol, an appropriate amount of pH regulator, and water for injection to get 1000 ml.
The preparation method is the same as Example 1.
The pH value is 6.5 and the mean particle size is 352 nm.
A total of 1.2 g of nimodipine, 50 g of soybean oil, 50 g of medium-chain triglyceride, 30 g of egg yolk lecithin, 0.0 g of disodium edetate, 0.0 g of oleic acid, 22.5 g of glycerol, an appropriate amount of pH regulator, and water for injection to get 1000 ml.
The preparation method is the same as Example 1.
The pH value is 8.5 and the mean particle size is 246 nm.
In order to determine the maximum drug loading capacity of the present invention without adding any cosolvent and the optimal formulation and process without adding any auxiliary emulsifier, the inventor has conducted numerous studies, and the study results are as follows:
1. A study on the optimal ratio of soybean oil to medium-chain triglyceride to get the best loading capacity was conducted.
As the solubility of nimodipine in soybean oil and medium-chain triglyceride varies, different ratios will cause difference in drug loading efficiency. In addition, excessive use of medium-chain triglyceride will cause the oil to leave out from the emulsion. On the basis of the formulation of Example 1, a study on oil phases in different ratios to get the optimal loading capacity was conducted.
Conclusion: The formulation is optimal when the ratio of soybean oil to medium-chain triglyceride is 4:6.
2. The effect of different contents of phosphatidylcholine (PC) and phosphatidyl ethanolamine in lecithin on the stability of the emulsion was investigated on the basis of the formulation of Example 1.
Conclusion: The lecithin emulsifying capacity is optimal when the contents of phosphatidylcholine (PC) and phosphatidyl ethanolamine (PE) are 70%-85% and 5%-18% respectively in the soya lecithin or egg yolk lecithin.
3. The effect of lecithin added with aqueous phase or oil phase on the composition injection of the present invention was investigated on the basis of the formulation of Example 1.
Conclusion: The composition of the present invention has higher δ-potential and higher stability when the lecithin is added with aqueous phase or together with oil phase.
4. The effect of the complexing agent on the value of anisidine of the composition injection of the present invention was investigated in Example 6.
Conclusion: The metal ion complexing agent can be utilized to realize antioxidation independently, considerably reducing the value of anisidine in the preparation, and improving the safety of the preparation. Adding other antioxidants cannot reduce the value of anisidine in the composition injection of the present invention.
In order to determine the stability of the preparation process of the present invention, the pilot-scale test was conducted according to Example 1, together with the dilution stability study and long-term stability study.
The test includes the following steps: transfer two parts of the composition injection of the present invention (each 30 ml) to a 250 ml volumetric flask, dilute to volume with 0.9% sodium chloride injection and 5% glucose injection, respectively and mix well to obtain the compatibility test solution. Measure the pH value and emulsion particle size, related substances and assay of the above solutions at 0 h, 2 h, 4 h, 6 h, 8 h and 12 h, respectively. The results are listed in the table below.
According to the results of the main tests on the diluted samples, there were no significant changes in the pH value, emulsion particle size, related substances, and assay of all diluted samples within 12 h. Therefore, the composition injection of the present invention diluted with glucose injection or sodium chloride injection in clinical use is safe and reliable within 12 h.
The composition injection of the present invention was placed under the condition of 25±2° C., protected from light, sampled once at 0, 3, 6, 9, 12, and 18 months, respectively, tested according to the key items of stability study, and compared with the values at 0 month.
It can be seen from the test results that after 18 months of long-term stability investigation at 25±2° C., all the indicators of the composition injection of the present invention meet the requirements, indicating that the quality of the composition injection of the present invention is stable under the storage conditions of 2˜25° C.
In order to verify the non-clinical safety of the composition injection of the present invention, special safety tests such as anaphylaxis, hemolysis and local (blood vessels, skin, mucosa, muscle, etc.) irritation, as well as zebrafish test and pharmacodynamic test on the model of subarachnoid hemorrhage in rats were carried out on the composition injection of the present invention as prepared in Example 1. The experimental results are as follows:
I. Special Safety Tests such as Anaphylaxis, Hemolysis and Local (Blood Vessel, Skin, Mucosa, Muscle, etc.) Irritation were Carried out on the Composition Injection of the Present Invention.
1. Anaphylaxis Test
1.1 Passive Anaphylaxis Test in Rats
After 48 hours of passive sensitization by intradermal injection of 0.1 mL of the corresponding antiserum into healthy and clean SD rats, each group was then intravenously injected with 8 and 4 mg/kg of the composition injection of the present invention, 8 and 4 mg/kg of nimodipine emulsion prepared by the patented process of the prior art (Application No: 200910021091.6, containing Tween 80 in the formulation), 100 mg/kg of bovine serum albumin, and 10 mL/kg of 0.9% NaCl Injection, together with 1 mL/animal of 1% Evans blue solution for the stimulation. The anatomical results after 30 minutes showed that there was no blue stain in the inner layer of the hack skin of rats in the 8 and 4 mg/kg dose groups of the composition injection of the present invention and the negative control group of 0.9% NaCl injection. However, significant blue stains (greater than 5 mm in diameter) appeared in the inner layer of the back skin of rats in the 8 and 4 mg/kg dose groups of nimodipine emulsion prepared by the patented process of the prior art and the bovine serum albumin positive control group, indicating a positive blue stain reaction. Under the condition of the doses in this test, sensitized rats had passive cutaneous anaphylaxis reactions to the nimodipine emulsion of the prior art, while no passive cutaneous anaphylaxis reaction to the composition injection of the present invention.
1.2 Active Systemic Anaphylaxis Test in Guinea Pigs
Healthy white guinea pigs were sensitized intraperitoneally of the composition injection of the present invention at doses of 4 and 2 mg/kg, respectively, every other day for 3 consecutive times. On Day 13 after the last sensitization, the composition injection of the present invention was single intravenous injected at the sensitizing dose for the stimulation. The sensitization and stimulation test methods of the nimodipine emulsion of the prior art were the same as above. The guinea pigs in the high-dose group of the composition injection of the present invention immediately (about 1 minute) developed prone immobility, followed by death and other similar anaphylaxis reactions, with a mortality of 100%. No significant abnormal reaction was observed in the guinea pigs in the low-dose group. However, both high- and low-dose groups of nimodipine emulsion of the prior art developed prone immobility, followed by death and other similar anaphylaxis reactions, with a mortality rate of 100% in the high dose group and 40% in the low dose group respectively. The guinea pigs in the high- and low-dose groups of the composition injection of the present invention, the nimodipine emulsion of the prior art and the bovine serum albumin positive control group had no obvious abnormal reaction during sensitization, and their average body weight at the first sensitization, last sensitization and challenge was similar to that of the 0.9% NaCl injection negative control group at the corresponding time (P>0.05). After the stimulation the guinea pigs in the bovine serum albumin positive control group had obvious anaphylaxis reaction symptoms, mainly manifested as restlessness, piloerection, shivering, scratching nose, sneezing, cough, shortness of breath, urination, lacrimation, dyspnea, instability of gait, wheezing, jumping, spasm and even death. The intensity of anaphylaxis reaction was ++˜++++,the death happened about 5 minutes after administration, and the surviving guinea pigs with anaphylaxis reaction gradually returned to normal within 30 minutes after administration, with a total reaction rate at 100%, and a mortality rate at 50%. Under the conditions of this test, guinea pigs had anaphylaxis reactions to 2 mg/kg of nimodipine emulsion of the prior art, while no anaphylaxis reaction to 2 mg/kg of the composition injection of the present invention.
2. Hemolysis Test
Operated in the conventional hemolysis test method used for drugs, each tube of 0.1˜0.5 mL of the composition injection of the present invention showed no hemolysis or agglutination within 3 hours, just the same as the negative control tube of 0.9% NaCl Injection. The nimodipine emulsion of the prior art and distilled water positive control tube all showed complete hemolysis at each time point. Under the conditions of the test, the nimodipine emulsion of the prior art had hemolysis and agglutination effects, while the composition injection of the present invention had no hemolysis and agglutination effects.
3. Vascular Irritation Test in Rabbits
Rabbits were slowly injected with 1 mg (10 mL)/(kg·d) of the composition injection of the present invention and the nimodipine emulsion of the prior art, respectively, once daily for 7 consecutive days, in the ear vein (blood vessel). Necropsy was performed 96 hours after drug withdrawal, and gross observation showed no obvious abnormality for nimodipine emulsion of both the present invention and the prior art. In histopathological examination, only 2 rabbits showed cloudy swelling in endothelial cells of ear vein close to the injection site, with mild edema in surrounding stroma, but without thrombosis, embolism nor a wide range of such serious irritant lesions as hemorrhage, edema, and necrosis, showing no significant difference compared with the 0.9% NaCl Injection control group. It was ranked as “<1” comprehensively judged according to the scoring criteria of a vascular irritation test. Under the condition of the test doses, according to the judgment in terms of “vascular irritation intensity”, both the composition injection of the present invention and the nimodipine emulsion of the prior art had no significant irritating effect on the ear veins (blood vessels) of rabbits.
4. Muscle irritation Test in Rabbits
Rabbits were injected with 0.1 mg (1 mL)/(kg·d) of the composition injection of the present invention and the nimodipine emulsion of the prior art, respectively, once daily for 7 consecutive days, in the quadriceps femoris of both the left and right legs. In the gross examination 48 hours after drug withdrawal, 8 rabbits showed congestion lesions of less than 0.5×1.0 cm at the injection site in one leg; other rabbits showed no significant congestion, swelling nor necrosis lesions at the injection site, with the sum of reaction grades for all quadriceps femoris up to 4, less than 6. Histopathological examination showed lesions mainly as small-focal or micro-focal interstitial hyperplasia and mononuclear cell infiltration in the quadriceps femoris at the injection site, with mild cloudy swelling or basophilic degeneration in muscle fiber in some lesions, only slightly more severe compared with the 0.9% NaCl Injection control group examined at the same period, but with a limited overall lesion range, without significant extensive muscle fiber degeneration, necrosis nor interstitial inflammatory infiltration, congestion, hemorrhage, edema nor other serious irritant lesions. Under the condition of the test doses, according to the grading standard of muscle irritation reaction, both the composition injection of the present invention and the nimodipine emulsion of the prior art had no significant irritation effect on quadriceps femoris of rabbits.
5. Summary:
(1) In the passive anaphylaxis test in rats, the sensitized animals showed passive cutaneous anaphylaxis reactions to nimodipine emulsion of the prior art, while no such reaction to the composition injection of the present invention. In the systemic active anaphylaxis test in guinea pigs, the animals in the high-dose group of the composition injection of the invention immediately (about 1 minute) developed prone immobility, followed by death and other similar anaphylaxis reactions, with a mortality of 100%, but no significant abnormal reactions were observed in the guinea pigs in the low-dose group. However, both high- and low-dose groups of nimodipine emulsion of the prior art developed prone immobility, followed by death and other similar anaphylaxis reactions, with a mortality rate of 100% in the high dose group and 40% in the low dose group respectively.
(2) The nimodipine emulsion of the prior art had hemolysis and agglutination effects, while the composition injection of the present invention had no hemolysis and agglutination effects.
(3) The vascular irritation test in rabbits showed that both the composition injection of the present invention and the nimodipine emulsion of the prior art had no significant irritating effect on the ear veins (blood vessels) of rabbits.
(4) The muscle irritation test in rabbits showed that both the composition injection of the present invention and the nimodipine emulsion of the prior art had no significant irritation effect on quadriceps femoris of rabbits.
II. The Cardiovascular Toxicity Study in the Zebrafish Model on the Composition Injection of the Present Invention is as Follows:
1. Administration to Fishes by Dissolving the Drug into the Water
1.1 Drugs
The drugs to be tested in this project include nimodipine drug substance, Nimotop (produced by Bayer), composition injection of the present invention (prepared according to Example 1) and blank emulsion, and nimodipine emulsion prepared by the patented process of the prior art (Application No. 200910021091.6, containing Tween 80 in the formulation). All were provided by Zhejiang Jiuxu Pharmaceutical Co., Ltd.
1.2 Test Instruments and Reagents
Dissecting microscope (SMZ645, Nikon, Japan); precision electron balance (CP214, Ohaus); six-well plate (Nest Biotech).
Zebrafish and Water for Fish Farming
The zebrafish larvae observed in the experiment were naturally incubated with embryos produced in the fertility experiment. Quality of water for fish farming: Add 200 mg instant sea salt into 1 L reverse osmosis water, with conductivity of 480-510 μS/cm, pH of 6.9-7.2 and hardness of 53.7-71.6 mg/L CaCO3. After completion of the experiment, zebrafish at various developmental stages were anesthetized and sacrificed with 0.25 mg/mL of tricaine methanesulfonate. The procedures for euthanasia complied with the American Veterinary Medical Association's (AVMA) code for euthanasia of animals.
1.3 Test Method
Wild-type AB zebrafish larvae at a certain stage were treated with the drugs to be tested for 24 hours, at five initial test concentrations, 0.1 μg/mL, 1 μg/mL, 10 μg/mL, 100 μg/mL and 500 μg/mL, with a blank control group respectively, and 30 zebrafish for each concentration of each drug. At the end of drug treatment, the number of zebrafish deaths in each experimental group was counted to provide a basis for the next experimental concentration design. The test concentration range of the drugs to be tested had an upper limit of 1,000 μg/mL (if the maximum solubility was less than 1,000 μg/mL, the highest solubility should prevail) and a lower limit of 0.001 μg/mL.
1.4 Comparison of Lethality in Zebrafish
Compared with the lower levels of maximum non-lethal concentration of other three types (2.5 μg/ml for nimodipine drug substance and nimodipine solution for injection, and 5.0 μg/ml for nimodipine emulsion by the prior art), the maximum non-lethal concentration of the injection with the invented composition was up to 10 μg/mL, which was 4 times that of the former two, and 2 times that of the latter, indicating that the toxicity induced by the injection of this invented composition in zebrafish is much less than that of nimodipine drug substance, nimodipine solution for injection, and nimodipine emulsion by the prior art.
1.5 Comparison of Heart Rate Reduction in Zebrafish
Zebrafish heart rate slowed as drug concentrations increased. Among them, the heart rate of zebrafish slowed down greatly with the increase of drug concentration of nimodipine drug substance, nimodipine solution for injection or nimodipine emulsion of the prior art, while the heart rate of zebrafish slowed down less with the increase of drug concentration of the composition injection of the present invention.
1.6 Comparison of Incidence of Atrial Arrest in Zebrafish
Nimodipine drug substance, nimodipine solution for injection, and nimodipine emulsion by prior art induced atrial arrest in some zebrafish at 2.5 μg/ml, and the incidence of atrial arrest in zebrafish induced by nimodipine drug substance, nimodipine solution for injection, and nimodipine emulsion by prior art hit 90%, 100%, and 70% respectively at 5.0 μg/ml. However, the composition injection of the present invention induced atrial arrest in some zebrafish at the concentration up to 20 μg/ml, and 100% atrial arrest at the concentration up to 40 μg/ml, both of which were obviously higher than that of nimodipine drug substance, nimodipine solution for injection, and nimodipine emulsion by prior art.
1.7 Comparison of Incidence of Pericardial Edema in Zebrafish
All the four types of drug induced pericardial edema in zebrafish with the incidence increased when elevating the drug concentration. Among them, the incidence of pericardial edema in zebrafish induced by nimodipine solution for injection increased the fastest with the elevated concentration, with pericardial edema in all zebrafish induced at 2.5 μg/ml; nimodipine drug substance took second place with pericardial edema in all zebrafish induced at 5.0 μg/ml, followed by nimodipine emulsion by prior art with pericardial edema in all zebrafish induced at 10.0 μg/ml; while the composition injection of the present invention saw the slowest increase with pericardial edema in all zebrafish induced at up to 20 μg/ml.
1.8 Summary
Experimental results showed that the composition injection of the present invention would also induce cardiovascular toxicity, such as decreased heart rate, atrial arrest, pericardial edema, and circulatory deficiency as the other three types of nimodipine (the drug substance, solution for injection, and nimodipine emulsion by prior art) did. But compared with the lower levels of maximum non-lethal concentration of other three types (2.5 μg/ml for nimodipine drug substance and nimodipine solution for injection, and 5.0 μg/ml for nimodipine emulsion by existing technology), the maximum non-lethal concentration of the injection with the invented composition was up to 10 μg/mL, which was 4 times that of the nimodipine drug substance and nimodipine solution for injection, and 2 times that of the nimodipine emulsion by existing technology, indicating that the toxicity induced by the injection of this invented composition in zebrafish is much less than that of nimodipine drug substance, nimodipine solution for injection, and nimodipine emulsion by existing technology.
2. Administration via Yolk Sac Injection
2.1 Test Design
Wild-type AB zebrafish larvae were treated with the drugs to be tested for 24 hours via yolk sac injection administration with a maximum dose volume of 40 nl, and the five initial test concentrations were: 0.1 mg/mL, 1 mg/mL, 10 mg/mL, 100 mg/mL, and 500 mg/mL, respectively. At the same time, a blank control group was set up, with 30 zebrafish treated at each concentration. At the end of drug treatment, the number of zebrafish deaths in each experimental group was counted to provide a basis for the next experimental concentration design. For the test concentration range of the drugs to be tested, the upper limit was 500 mg/ml (if the maximum solubility was less than 500 mg/ml, the highest solubility should prevail), and the lower limit was 0.001 mg/ml.
2.2 Cardiovascular Effect of Nimodipine Drug Substance on Zebrafish
2.2.1 10 nl was administered via yolk sac injection. After treatment for a certain period of time, 10 zebrafish were randomly selected to have their heart rates counted, and their relative heart rates were calculated for comparison. The results showed that the heart rate slowed down when the concentration reached 32 mg/ml, with that of the rest of the drug-treated groups being normal. The results are listed in Table 13.
Positive Control: Terfenadine Tablets
2.2.2 Mortality statistics performed at the end of the experiment showed that the lethality increased with elevated concentrations in the 4.0 mg/ml and higher concentration groups. The results are listed in Table 14.
Positive Control: Terfenadine Tablets
2.2.3 10 zebrafish in each group were randomly selected and observed under the dissecting microscope. The results showed that the incidence of pericardial edema increased with elevated concentrations in the treatment groups, and the incidence of pericardial edema reached 100% in the highest concentration group of 32 mg/ml, accompanied by circulatory insufficiency in zebrafish. The results are listed in Table 15.
Positive Control: Terfenadine Tablets
2.3 Cardiovascular Effect of Nimodipine Solution for Injection (Nimotop) on Zebrafish
2.3.1 Since the highest concentration of Nimotop was only 0.2 mg/ml and its solvent could not be prepared, it was administered via injection of different volumes at the highest concentration. Since the most abundant component in the solvent was 23.7% ethanol, 24% ethanol solution was prepared as the solvent control group to prove that ethanol at this concentration would not affect the experiment. After treatment tier a certain period of time, 10 zebrafish were randomly selected to have their heart rates counted, and their relative heart rates were calculated for comparison. The results showed that no abnormalities were observed in all groups except for the positive control group (terfenadine tablets). The results are listed in Table 16.
2.3.2 Mortality statistics performed at the end of the experiment showed that no dead individuals were observed. The results are listed in Table 17.
2.3.3 10 zebrafish in each group were randomly selected and observed under the dissecting microscope. The results showed that except for the positive control group (terfenadine tablets), only 40% of the individuals in the 40 nl group developed pericardial edema, accompanied by circulatory insufficiency and decreased blood flow. The results are listed in Table 18.
2.4 Cardiovascular Effect of Composition Injection of Present Invention on Zebrafish
Three formal experimental concentrations were set. After treatment for a certain period of time, 10 zebrafish were randomly selected to have their heart rates counted, and their relative heart rates were calculated for comparison. The results showed that no abnormalities were observed in all groups except for the positive control group (terfenadine tablets). No dead individual was observed at the end of the experiment, and no abnormalities were observed in all groups except the positive control group. The results are listed in Table 19.
2.5 Summary
In the yolk sac injection administration experiment, the lethality in zebrafish increased with elevated concentrations in the 4.0 mg/mL and higher concentration groups of nimodipine drug substance, while pericardial edema and circulatory deficiency could be induced. Nimodipine drug substance induced pericardial edema in 30% of individuals at the administration concentration of 2.0 mg/ml (67 mg/kg), and the nimodipine solution for injection induced pericardial edema in 40% of individuals at the maximum administration dose of 40 nl (26.7 mg/kg), while no cardiovascular toxicity was observed at the maximum administration dose (106.7 mg/kg) of the composition injection of the present invention, indicating that the cardiovascular toxicity of the composition injection of the present invention in zebrafish was less than that of nimodipine solution for injection and nimodipine drug substance.
3. Pharmacodynamic Study of Composition Injection of Present Invention on Rat Subarachnoid Hemorrhage Model
3.1 Pharmacodynamic Test Method
3.1.1 Modeling Method
Male SD rats weighing 160-200 g were anesthetized to expose the skull, which was perforated (at the parietal bone behind the lambdoidal suture) with an approximately 1 mm bone drill, but without perforating the dura mater. At the same time, 500 μL of autologous blood was collected from the fundus venous plexus with a 1 mL syringe and inserted into the skull along the bone hole to a depth of 3-4 mm. Biogum was used for sealing to prevent leakage, and the blood was injected slowly, with attention paid to observation. Then Pericam PSI laser microcirculation blood flow imager was used to determine cerebral blood flow in rats.
3.1.2 Grouping and Administration
The experimental animals were randomly divided into 8 groups: the control group with only skull exposed but no blood injection; high, medium, and low dose groups of nimodipine solution for injection; high, medium, and low dose groups of the composition injection of the present invention; and the model group of normal saline. More than 10 rats survived after successful modeling in each group. The administration method and dosage of each group are as follows.
Nimodipine Solution for Injection Group: 2 mg/kg bw for high dose, 1 mg/kg bw for medium dose, and 0.5 mg/kg bw for low dose; the drug concentration was 1 mg/5 mL.
Composition Injection of Present Invention Group: The composition injection of the present invention was diluted to 1 mg/5 mL with normal saline prior to use. 2 mg/kg bw for high dose, 1 mg/kg bw for medium dose, and 0.5 mg/kg bw for low dose.
Model Group: 1 mL/100 g bw of normal saline was injected into the tail vein.
Administration volume and method: 1 mL/100 g bw for high dose, 0.5 mL/100 g bw for medium dose, and 0.25 mL/100 g bw for low dose. The administration via tail vein injection was conducted at the above doses after about 30 min, 48 h, and 96 h after modeling.
3.2 Results
3.2.1 Determination Results of Cerebral Blood Flow
See Table 20 for the determination results of cerebral blood flow before administration after modeling in each group.
After modeling, there were highly significant differences in blood flow within the whole cranial region and sagittal suture region (basilar artery) between each group and the normal group. It indicated that the modeling was successful and the cerebral blood flow perfusion decreased significantly in all groups.
There was no significant difference in blood flow within the whole cranial region and sagittal suture region (basilar artery) between each group of the composition of the present invention and the model group. The blood flow in the sagittal suture region (basilar artery) of the medium dose group of nimodipine solution for injection was significantly different from that of the model group, with no significant differences in the other groups, indicating that the blood flow in the basilar artery of the medium dose group of nimodipine solution for injection after modeling was significantly different from that of the model group.
Cerebral blood flow was determined prior to administration, with timing, and blood flow in the whole cranial region and sagittal suture region was determined again 30 min after administration. See Table 21 and Table 22 below for the results of the one-way ANOVA using EXCEL software.
As seen in Table 21, cerebral blood flow increased to a certain extent in all groups 30 min after administration compared to that before administration. There was no significant difference in the improvement of cerebral blood flow before and after the administration between each dose group of nimodipine solution for injection and the composition of the present invention.
As seen in Table 22, there was no significant difference in cerebral blood flow between groups after administration. There was also no significant difference between the same dose groups of nimodipine solution for injection and the composition of the present invention.
After 10 d of modeling, the laser microcirculation blood flow imager was used to determine whole brain and midbrain blood flow in the high dose group of nimodipine solution for injection (3 rats) and the high dose group of the composition of the present invention (4 rats). See Table 23 below for the results of the one-way ANOVA using EXCEL software.
It can be seen from Table 23 that the blood flow in the whole cranial region and sagittal suture region (basilar artery) after 10 days in the high dose groups of nimodipine solution for injection and the present invention composition (3 doses) was basically the same, without significant difference.
The cerebral blood flow of the high dose groups of nimodipine solution for injection and the present invention composition before and after modeling and before and after administration are shown in Table 24, and the changes of cerebral blood flow are shown in
The results show that the cerebral blood flow of the whole cranial region and sagittal suture region (basilar artery) of the animals in the high dose groups of both nimodipine solution for injection and the present invention composition decreased significantly after modeling, all of which increased to a certain extent after administration. The improvement effect of the present invention composition was slightly better than that of nimodipine solution for injection at the same dose, but the two groups were basically the same, without significant difference.
3.2.2 Measurement Results of Cerebral Vasospasm Degree
The brain tissue was dehydrated, embedded in paraffin, and the brainstem tissue sections containing the basilar artery were prepared and observed wider a microscope after HE staining and mounting, and the circumference and area of the basilar artery vessels were measured with an image analysis system to determine the degree of cerebral vasospasm. For the results, see Table 25 below.
From the above table, it can he seen that compared with the normal group, the basilar artery circumference and area in the model group were greatly decreased, indicating that intracranial blood injection induced basilar artery contraction in rats. For section circumference of basilar artery, compared with the model group, the high, medium and low doses of nimodipine solution for injection had significant improvement effect, of which the high dose group had a very significant improvement effect; and the low, medium and high doses of the composition of the present invention also had significant improvement effect.
Because the vessels were easy to deform during later slide preparation, the cross-sectional area of vessels in some animals varied greatly, increasing the intra group SD. Compared with the model group, the cross-sectional area of basilar artery was significantly improved only in the high dose groups of nimodipine solution for injection and the composition of the present invention.
There was no significant difference between the groups at the same dose, but with a certain dose-effect relationship. The circumference and area of the basilar artery increased with the increase of dose.
Based on the improvement on the degree of cerebral vasospasm (circumference and area of basilar artery) in each group, the rank of efficacy is as follows: high dose of nimodipine solution for injection≈high dose of the present invention composition>medium dose of the present invention composition≈medium dose of nimodipine solution for injection≈low dose of nimodipine solution for injection>low dose of the present invention composition.
3.2.3 Results of Behavioral Measures
The rotarod endurance test was performed in the laboratory animals 24 hours, 72 hours, and 5 days after dosing. Refer to Table 26 for results.
The results of rotarod endurance test show that, compared with the normal group, the rotarod endurance of the model group after modeling decreased significantly after modeling, with a tendency to recover slowly over time.
Twenty-four (24) hours after the first dose, all dose groups had some recovery compared with the model group. Among which, the medium and high dose groups of nimodipine solution for injection, the medium and high dose groups of the present invention composition had significant improvement. There was a significant dose-response relationship among different doses.
After 2 doses (72 hours later), all dose groups also had some recovery compared with the model group. Among which, the high dose group of nimodipine solution for injection, the medium and high dose groups of the present invention composition had significant improvement. There was a certain dose-response relationship among different doses.
After 3 doses (after 5 days), all dose groups also had some recovery compared with the model group. Among which, the high dose group of the present invention composition had significant improvement. There was a certain dose-response relationship among different doses.
Open field spontaneous activity test was performed in the laboratory animals 24 hours, 72 hours and 5 days after dosing. The video monitoring system was enabled to record the activity distance and duration of rats within 5 min. The results are shown in Tables 27 and 28.
From the results in Tables 27 and 28, it can be seen that, compared with the normal group, the activity distance and duration within 5 minutes in the model group after modeling were significantly decreased, and there was no significant trend to change the mobility over time.
Distance and duration of activity had been improved, overall mobility had been increased, and there was also a slight improvement with the increase of doses. Compared with the model group, the activity distance of the high dose group of the present invention composition was significantly improved at 5 d after dosing; the activity duration of the high dose group of the nimodipine solution for injection and the medium dose group of the present invention composition was also significantly improved, but without significant difference.
3.3 Adverse Reactions in Pharmacodynamic Tests
Nimodipine solution for injection contained high concentrations of ethanol, thus rendering a strong “anesthetic” effect in intravenous injection, from which it took about 10-30 min for rats to recover slowly after injection. For nimodipine solution for injection, the experimental results showed that there were significant toxic and adverse effects in the high dose group, with the death of several animals during the administration. After multiple doses of the nimodipine solution for injection, several animals developed significant phlebitis and tail ulceration. However, for the injection with the composition of this invention, there were no deaths or any other observed adverse effects in every dose group during the administration.
In summary, the efficacy of the composition injection of the present invention at the same dose is basically equivalent to that of nimodipine solution for injection, without significant difference. However, no toxic side effects and other adverse reactions were observed in the composition injection of the present invention during the test. Therefore, the composition injection of the present invention has the same efficacy as the commercial nimodipine solution for injection and the nimodipine emulsion injection by the prior art, but with better safety.
IV. Determination of the Plasma Concentration of the Composition Injection of the Present Invention
Male SD rats were selected and acclimated for 2 days, and then anesthetized by intraperitoneal injection of 5% chloral hydrate (prepared with normal saline) with the same anesthetic dose as above. After anesthesia, the animals were numbered and divided into the present invention composition group and the Nimotop (nimodipine solution for injection) group. The rats were intravenously injected into the tail vein at a dose of 2 mg/kg bw. At 10, 30, 90, and 120 min after dosing, 0.3 ml blood was collected from the fundus venous plexus of rat inner canthus and placed into a pre-heparinized blood collection tube, centrifuged at 4000 rpm for 10 min, and the upper plasma was taken and stored at −80° C.
Nimodipine plasma samples were assayed by UPLC-PDA method. The sample plasma was processed one by one and injected for analysis, and the concentration of nimodipine in the plasma was calculated. The results are shown in Table 29. The plasma concentration-time curves were plotted against the plasma concentration (ng/ml) versus time (min). The results are shown in the attached
It can be seen from Table 29 and
| Number | Date | Country | Kind |
|---|---|---|---|
| 201811046629.4 | Sep 2018 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2019/104760 | 9/6/2019 | WO | 00 |
