Patent Grant
7687542
The present application claims priority to U.S. Ser. No. 11/180,996, filed Jul. 13, 2005 (pending), and U.S. Ser. No. 11/030,537, filed Jan. 5, 2005 (pending). In turn, the foregoing applications claim priority to U.S. Ser. No. 09/524,747, filed Mar. 14, 2000 (granted as U.S. Pat. No. 6,974,595), which claims priority to U.S. Ser. No. 09/192,493, filed Nov. 17, 1998 (abandoned), which claims priority to PCT/EP97/02709, filed May 15, 1997, which claims priority to Italian App. No. MI96A000992, filed May 17, 1996. The contents of the foregoing applications are incorporated by reference as if fully set forth herein.
The present invention relates to excipients for the production of rapidly bioavailable solid oral dosage forms of diclofenac. In particular, the invention relates to the use of excipients that promote the bioavailability of such formulations, including alkaline buffering agents, gas forming excipients, hygroscopic excipients, water soluble diluents, wetting agents, and particular pharmaceutically acceptable salts.
Pharmaceutical excipients play a crucial role in the development of solid oral dosage forms. Excipients influence the processability of the powders and granulates used to form solid oral dosage forms, and are selected to assure uniform weights and drug content among unit doses within and among batches. Excipients also influence numerous physical properties of a drug dosage form, including hardness, friability, and ease of disintegration/dissolution. Excipients also influence the bioavailability of a drug when orally ingested by impacting the rate at which the product dissolves in the gastrointestinal tract, the solubility of the drug in the gastrointestinal tract, and the portion of the GI tract in which the drug is released.
When rapid bioavailability is desired, preferred modes of administration include parenteral, inhalation, mucosal and buccal administration. Tablets and capsules are generally available only in immediate release, extended release, and delayed release formats, and are not typically employed when rapid bioavailability is desired because of the time it takes for the dosage form to dissolve, and the resulting delay in gastrointestinal absorption. The present inventors recently proposed in PCT/EP97/02709 (published as WO 97/44023) a novel delivery system for orally delivering diclofenac that employed an alkali metal bicarbonate to accelerate the bioavailability of diclofenac from numerous oral dosage forms, including tablets, powders for dissolution in water, gum, chewable tablets, and liquids, among others. The current application claims priority to WO 97/44023 and incorporates the application's contents by reference.
Currently marketed forms of diclofenac tablets contain various pharmaceutical excipients. For example, diclofenac sodium 25 mg film-coated tablets marketed by Novartis Healthcare as Novapirina® contain colloidal silica, cellulose, lactose, magnesium stearate, polyvidone, sodium carboxymethylcellulose, hydroxypropylmethylcellulose, polysorbate, talc, and titanium dioxide.
Diclofenac potassium 50 mg film-coated tablets marketed variously as Cataflam,® Voltfast,® and Voltaren® Rapid contain calcium phosphate, saccharose, maize starch, talc, sodium carboxymethylcellulose, colloidal anhydrous silica, polyvinylpyrrolidone, microcrystalline cellulose, magnesium stearate, polyethylene glycol, titanium dioxide, and iron oxide red.
Diclofenac potassium 12.5 mg film-coated tablets marketed as Voltaren Dolo® contain colloidal anhydrous silica, lactose, maize starch, sodium starch glycolate, polyvidone, magnesium stearate, microcrystalline cellulose, hydroxypropylmethylcellulose, titanium dioxide, macrogol, polysorbate 80, and maltodextrin.
Diclofenac free acid 46.5 mg dispersible tablets (equivalent to 50 mg as sodium salt) marketed as Voltarol® contain microcrystalline cellulose, croscarmellose sodium, sodium starch glycollate, sodium saccharin, cellulose, hydrogenated castor oil, talc, silicon dioxide, erythrosine, aluminium oxide, and blackcurrant flavor.
Each of these commercially marketed products employ traditional disintegrants such as croscarmellose sodium, crospovidone and sodium starch glycolate to aid in the break up of the compacted mass and expose the active ingredient to the solvent. The formulations are not designed to expose the active ingredient by dissolving the excipient base. Even the diclofenac potassium product marketed as Voltfast, which is marketed based on its fast onset of action, contains excipients such as calcium phosphate that are practically insoluble. While Voltfast® does contain saccharose, which is very soluble in water, this ingredient is only present only in a minor amount in the outer film coating.
Mannitol is a water soluble, non-hygroscopic diluent that produces a semi-sweet, smooth, cool taste, that has been used for in chewable tablet formulations prepared by direct compression and orally disintegrating tablets (ODTs). Sangekar et al., J. Pharm. Sci., vol. 61, pp. 939-944 (1972). Joshi et al. report that mannitol is often preferred over lactose because of its low hygroscopicity, drug compatibility, compressibility, sweetness, and relatively slower dissolution kinetics. Joshi et al., Pharmaceutical Technology (June 2004).
Adkin et al. studied the effect of different concentrations of mannitol in solution on small intestinal transit, in Pharmaceutical Research, Vol. 12, No. 3 (1995) and Jnl. Pharm. Sci., Vol. 84, No. 12 (1995), and determined that mannitol reduced the transit time through the small intestine for solutions containing mannitol. According to the authors, this reduced transit time had a significant potential for reduced biological uptake, especially for drugs absorbed through the small intestine such as cimetidine.
The present invention provides various methods for enhancing the bioavailability of tablet and capsule dosage forms of diclofenac by employing in the formulation gas forming alkaline buffering agents, hygroscopic excipients, freely soluble diluents, wetting agents, and combinations of the foregoing, that are especially useful in the treatment of acute pain where rapid onset of relief is desired. The formulations are rapidly bioavailable, and can generally be characterized by (i) a disintegration time of less than about 15 minutes when tested according to USP 28 <701>, (ii) a tmax of from about 15 to about 40 minutes, and (iii) a Cmax of from about 1500 to about 2500 ng/ml for a 50 mg dose, normalized to from about 0.03 liter−1 to about 0.05 liter−1.
Therefore, in one embodiment the invention provides a method of treating pain comprising orally administering diclofenac potassium in an intact rapidly bioavailable tablet or capsule dosage form characterized by (i) a tmax of from about 10 to about 30 minutes, (ii) a Cmax of from about 1700 to about 2500 ng/ml for a 50 mg. dose, and preferably (iii) a disintegration or dissolution time of less than about 15 minutes when tested according to USP 28 <701> or USP 28 <711>, wherein the dosage form meets one or more of the following conditions:
Additional advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
As used in the specification and claims, the singular forms a, an and the include plural references unless the context clearly dictates otherwise. For example, the term a pharmaceutical excipient may refer to one or more pharmaceutical excipients for use in the presently disclosed formulations and methods.
USP means the United States Pharmacopeia and National Formulary (USP 28-NF 23). Rockville, Md.: United States Pharmacopeia Convention; 2004, unless stated to the contrary. USP 28 <701> refers to physical test 701, disintegration, contained on pages 2411-2412 of the USP.
A dosage form, as used herein, refers to a formulation that is ready for administration to a subject. As used herein, it specifically refers to solid dosage forms, including, but not limited to, tablets, powders and capsules. An “intact” dosage form refers to a dosage form which is ingested in the form it is provided. Intact dosage forms are therefore to be distinguished from orally disintegrating tablets which disintegrate in the mouth before being ingested, or effervescent tablets which are dissolved in water before being ingested.
Cmax refers to the maximum plasma concentration of a drug following the oral administration of the solid oral dosage form to patients. Normalized Cmax refers to the value obtained by dividing Cmax into the dosage strength of the solid oral dosage form.
AUC refers to the area under the curve that tracks the plasma concentration (ng/ml) of a drug over a given time following the oral administration of the solid oral dosage form to patients. AUC can be measured from 0 to 12 hours or from 0 to 24 hrs following the administration and in these cases are referred to as AUC ((0-12)) or AUC ((0-24)), respectively.
Normalized AUC is obtained by dividing the AUC into the dosage strength of the solid oral dosage form of the drug. For example, if the AUC ((0-12)) is 160 hr·ng/ml following the oral administration of a solid oral dosage form containing 200 mg of active ingredient, the normalized AUC ((0-12)) is 0.8 hr·ng/ml/mg.
Diclofenac is chemically described as [(2,6-dichloro-anilino)-2-phenyl]-2-acetic acid, and is represented by the following chemical structure:
When used herein, the term diclofenac means the acetic acid form of diclofenac, and any of its pharmaceutically acceptable salts. Therefore, when a weight ratio is given, it will be understood that the ratio refers to the relative weight of diclofenac acid in the ratio, and the relative weight of diclofenac potassium (or other salt) in the ratio.
As discussed above, the invention provides (i) methods for treating pain using diclofenac potassium, (ii) dosage forms of diclofenac potassium that are useful for treating pain, and (iii) methods of manufacturing such dosage forms. Although the compositions of the present invention are useful in chronic pain conditions such as rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis; and periarticular disorders such as bursitis and tendonitis; they are particularly useful in the treatment of acute pain conditions, including soft tissue disorders such as sprains and strains, migraine attacks, and other painful conditions such as renal colic, acute gout, dysmenorrhoea, and following some surgical procedures.
Therefore, in one embodiment the invention provides a method of treating pain comprising orally administering diclofenac potassium in an intact tablet or capsule dosage form characterized by (i) a tmax of from about 10 to about 30 minutes, (ii) a Cmax of from about 1700 to about 2500 ng/ml for a 50 mg. dose, and preferably (iii) a disintegration or dissolution time of less than about 15 minutes when tested according to USP 28 <701> or USP 28 <711>, wherein the dosage form meets one or more of the following conditions:
Mean tmax attained by the formulations of the present invention is preferably less than about 40 minutes, 35 minutes, 30 minutes, 25 minutes or 20 minutes, and greater than about 5 minutes, 10 minutes or 15 minutes. Mean tmax is preferably from about 5 to about 30 minutes, or from about 13 to about 27 minutes.
Furthermore, the tmax of the formulations of the present invention show a coefficient of variation which is about 44-86% lower than presently marketed formulations. (The corresponding coefficient of variation is normally in the range of 70-90%, which means that the Tmax is strongly variable and dependent on the physical characteristics of the patient (Physicians' Desk Reference, 52 edition, 1998, pag. 1831)). The inter-subject coefficient of variability for said tmax is preferably less than about 80, 75, 70, 60, 50, 49, 46, 40, 35, 30% or 25%.
Cmax
Mean Cmax attained by the formulations of the present invention is preferably greater than about 1400 ng/ml (0.028 liter−1), 1500 ng/ml (0.03 liter−1), 1600 ng/ml (0.032 liter−1) or 1700 ng/ml (0.034 liter−1), and less than about 2500 ng/ml (0.05 liter−1) or 2300 ng/ml (0.046 liter−1), for a 50 mg. formulation. A preferred range is 1700-2500 or 1700-2300 ng/ml for a 50 mg. formulation. In contrast to other commercially marketed diclofenac formulations, the formulations of the present invention preferably display only one meaningful peak blood concentration after ingestion. The inter-subject coefficient of variability for said Cmax preferably is less than about 70, 60, 50, 45 or 40%.
In addition, the Cmax observed for the formulations of the present invention preferably demonstrate only one concentration peak when Cmax is plotted against time. As can be seen by comparing the formulations of the present invention (
Preferred Cmax and tmax ranges for various dosage forms of the invention are set forth below in Table A:
Disintegration Time Time (USP 28 <701>)
Disintegration times for the dosage forms of the present invention, when tested according to USP 28 <701>, are preferably less than about 20 minutes, 15 minutes, 10 minutes, 5 minutes, or even 4 minutes, and greater than about 1, 2 or 3 minutes, most preferably from about 3 to about 5 minutes. In one particular embodiment, the dosage form is a tablet, and the tablet has a disintegration time that increases as the hardness of the tablet decreases. In another embodiment, the tablet has a disintegration time that increases as the moisture absorption by the tablet increases.
Dissolution Time (USP 28 <711>)
Dissolution times for the dosage forms of the present invention, when tested according to USP 28 <711>, based on the time it takes to dissolve 90 or 95 wt. % of the drug substance, are preferably less than about 20 minutes, 15 minutes, 10 minutes, 5 minutes, or even 3 minutes, and greater than about 1 or 2 minutes. In a preferred embodiment the dissolution profile of the dosage forms of the present invention is as follows: not less than 85, 90 or 95% after 15 minutes in simulated intestinal fluid (i.e. water) at pH=6.8.
Means for Generating a Gaseous and Alkaline Environment
In one embodiment the dosage forms of the present invention comprise means for generating a gaseous and alkaline environment for said diclofenac potassium when orally ingested into the stomach. Suitable means for generating a gaseous and alkaline environment that is not harmful to the gastrointestinal mucosa. These include, but are not limited to, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, calcium carbonate, magnesium carbonate, sodium glycine carbonate, disodium hydrogen phosphate, sodium dihydrogen phosphate, and mixtures thereof. Suitable gas generating means are not limited to those which are based upon a reaction which forms carbon dioxide. Reactants which evolve oxygen or other gases and which are safe for human consumption are also considered within the scope of the present invention.
The means for generating an alkaline and gaseous environment are typically employed in a weight ratio relative to the diclofenac of greater than about 1:5, 2:5, 2:1, 3:1 or 5:1. If desired, an upper limit on the buffer:diclofenac ratio can be placed at about 20:1, 10:1, 5:1, 1:1, 4:5 or 3:5. Ranges can be selected from any two of the foregoing values that are mathematically possible. In a preferred embodiment, the buffer:diclofenac weight ratio ranges from about 1:5 to about 4:5.
The hygroscopic excipient is typically employed in a weight ratio relative to the diclofenac of greater than about 1:5, 2:5, 2:1, 3:1 or 5:1. If desired, an upper limit on the excipient:diclofenac ratio can be placed at about 20:1, 10:1, 5:1, 1:1, 4:5 or 3:5. Ranges can be selected from any two of the foregoing values that are mathematically possible. In a preferred embodiment, the excipient:diclofenac weight ratio ranges from about 1:5 to about 4:5. As a total percentage of the dosage form, the means for generating a gaseous and alkaline environment preferably makes up greater than about 5, 7 or 9 wt. % of the dosage form formulation, and less than about 25, 20 or 15 wt. % of the formulation. The means preferably yields a pH greater than about 7.0, 7.5, 7.8 or 8.0, and less than about 9.2, 9.0, 8.8 or 8.5 when the dosage form is mixed with 50 ml of water at 25 degrees Celsius. Alternatively, the means preferably yields a pH greater than about 6.8, 7.0, 7.2, or 7.5, and less than about 8.8, 8.5, 8.3 or 8.0 when the dosage form is mixed with 200 ml of water at 25 degrees Celsius.
The results of pH testing in different quantities of water are reported below in Table B:
Hygroscopic Excipients
In a second principal embodiment the invention provides a method of treating acute pain comprising orally administering diclofenac potassium in an intact rapidly bioavailable tablet or capsule dosage form, wherein said dosage form comprises from about 5 to about 25 wt. % of a hygroscopic excipient.
There are many methods of quantitative evaluation of hygroscopicity of solid products without measuring the hygroscopic point. The most widely used method for measuring the hygroscopicity of a material is based on measuring the weight gain of a solid sample in a humidity chamber. Products that at relative humidity of 80% (RH=80%) demonstrate low water absorption ability (lower than 1% during 24 hrs) have a hygroscopic point below 80% (j<80% RH) and are not considered hygroscopic within the meaning of this invention. A hygroscopic excipient could thus have the ability to absorb greater than about 1 wt. %, 3 wt. %, 5 wt. % or 7 wt. % moisture within a twenty four hour period in a humidity chamber maintained at 80% RH and 25° C. Alternatively, a hygroscopic excipient could be defined as an excipient that is able to absorb greater than about 0.75 wt. %, 1 wt. %, 2 wt. %, 3 wt. % or 4 wt. % moisture within a twenty four hour period in a humidity chamber maintained at 60% RH and 25° C.
Various hygroscopic excipients could be used in practicing the present invention, including various water-soluble hygroscopic polyhydroxy compounds or esters thereof such as glycerol and its mono- and diesters derived from low molecular weight carboxylic acids, e.g., monoacetin and diacetin (respectively, glyceryl monoacetate and glyceryl diacetate), ethylene glycol, diethylene glycol, triethylene glycol, 1,3-propanediol, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, and the like. Other examples of hygroscopic or water-swellable materials include pharmaceutically acceptable disintegrants such as fumed silica, silica gel, crosslinked polyvinylpyrrolidone, starch NF, hygroscopic sugar and ion exchange resins. In a preferred embodiment the hygroscopic excipient is potassium bicarbonate or sodium bicarbonate.
The hygroscopic excipient is typically employed in a weight ratio relative to the diclofenac of greater than about 1:5, 2:5, 2:1, 3:1 or 5:1. If desired, an upper limit on the excipient:diclofenac ratio can be placed at about 20:1, 10:1, 5:1, 1:1, 4:5 or 3:5. Ranges can be selected from any two of the foregoing values that are mathematically possible. In a preferred embodiment, the excipient:diclofenac weight ratio ranges from about 1:5 to about 4:5. As a total percentage of the dosage form, the hygroscopic excipient preferably makes up greater than about 5, 7 or 9 wt. % of the dosage form formulation, and less than about 25, 20 or 15 wt. % of the formulation.
Hygroscopic Dosage Forms
In a third principal embodiment the invention provides a method of treating acute pain comprising orally administering diclofenac potassium in an intact rapidly bioavailable hygroscopic tablet or capsule dosage form. Once again, there are many methods of quantitative evaluation of hygroscopicity. In the present invention, dosage forms that at relative humidity of 80% (RH=80%) demonstrate low water absorption ability (lower than 1% during 24 hrs) have hygroscopic point below 80% (j<80% RH) and are not hygroscopic at normal conditions. A hygroscopic dosage form could thus have the ability to absorb greater than about 1 wt. %, 1.25 wt. %, 1.5 wt. % or 2 wt. % moisture within a twenty four hour period in a humidity chamber maintained at 80% RH and 25° C. Alternatively, a hygroscopic dosage form could be defined as a dosage form that is able to absorb greater than about 0.50 wt. %, 0.75 wt. %, 1 wt. %, 1.25 wt. %, or 1.5 wt. % moisture within a twenty four hour period in a humidity chamber maintained at 60% RH and 25° C.
Tests performed on 50 mg. diclofenac potassium tablets of the present invention maintained at 25° C. and 60% RH over twenty four hours showed an increase in KF (% water) from 1.995% (at time zero) to 3.456% (after 24 hours). Tests performed on 50 mg. diclofenac potassium capsules of the present invention maintained at 25° C. and 60% RH over twenty four hours showed an increase in KF (% water) from 1.905% (at time zero) to 2.93% (after 24 hrs.).
Freely Soluble Excipients
In a fourth principal embodiment the invention provides a method of treating acute pain comprising orally administering diclofenac potassium in an intact rapidly bioavailable tablet or capsule dosage form, wherein said dosage form comprises at least 20 wt. %, 30 wt. %, 40 wt. %, 50 wt. %, or 60 wt. % of excipients that are freely soluble in water, or greater. An excipient is considered freely soluble in the context of this application if 1 part of excipient is soluble in 1-10 parts of water at 20° C.
Examples of freely soluble excipients thus include mannitol, dextrates (i.e. a purified mixture of saccharides resulting from the controlled enzymatic hydrolysis of starch), dextrin, dextrose, fructose, lactilol, lactose anhydrous, sorbitol, sucrose, and compressible sugar. Of these, mannitol and lactilol are particularly preferred due to their beneficial non-hygroscopic properties, which improves their processing and handling during the manufacturing process.
In one embodiment the invention is defined by the combined weight percentage of hygroscopic and freely soluble diluents in the dosage form, and the weight ratio of hygroscopic diluent to freely soluble diluent. In a preferred embodiment the dosage form will comprise from about 30 to about 80 wt. % of the combined hygroscopic diluent and freely soluble diluent, from about 35 to about 75 wt. % of the combined hygroscopic diluent and freely soluble diluent, or from about from about 40 to about 70 wt. % of the combined hygroscopic diluent and freely soluble diluent. In addition, the hygroscopic diluent and freely soluble excipient will preferably be present in a weight ratio of from about 1:20 to about 5:1, from about 1:10 to about 3:1, from about 1:8 to about 1:1, from about 1:8 to about 1:2, or from about 1:4 to about 1:1.
Wetting Agents
In another principal embodiment the invention provides a method of treating acute pain comprising orally administering diclofenac potassium in an intact rapidly bioavailable tablet or capsule dosage form, wherein said dosage form comprises a wetting agent or surfactant. Surfactants which may be used in the present invention generally include all pharmaceutically-acceptable surfactants, although preferred surfactants will have an HLB value of at least 10 or 12, and preferably at least about 14 or 15. In certain preferred embodiments, the HLB value of the surfactant is from about 15 to 60, and in further embodiments is most preferably from about 16 to about 50. Suitable pharmaceutically-acceptable anionic surfactants include, for example, those containing carboxylate, sulfonate, and sulfate ions. Those containing carboxylate ions are sometimes referred to as soaps and are generally prepared by saponification of natural fatty acid glycerides in alkaline solutions. The most common cations associated with these surfactants are sodium, potassium, ammonium and triethanolamine. The chain length of the fatty acids typically range from 12 to 18. Although a large number of alkyl sulfates are available as surfactants, one particularly preferred surfactant is sodium lauryl sulfate, which has an HLB value of about 40. Other suitable wetting agents include glyceryl monooleate, sorbitan ester, docusate sodium, and cetrimide.
Diclofenac Potassium
While diclofenac acid or any of diclofenac's pharmaceutically acceptable salts could be used when practicing the current invention, diclofenac potassium is preferred. Other pharmaceutically acceptable salts include those of sodium and other alkali and alkaline earth metals, or salts of organic nature, such as the salts of basic amino acids, such as lysine, arginine and omithine. In a preferred embodiment, 10-60 mg. or 50 mg. of diclofenac potassium is used in the final dosage form, although other amounts could be used including 12.5, 25, 37.5, 75 or 100 mg. The amount of diclofenac potassium preferably does not vary by more than about 95-105% among unit dosage forms.
In general, the raw material will be a powder that exhibits no more than 0.5 wt. % loss on drying, and in which not less than 90% of the particles are less than 500 micrometers in diameter, not less than 40% and not more than 70% of the particles are less than 200 micrometers in diameter, not less than 35% and not more than 65% of the particles are less than 150 micrometers in diameter, and not less than 30% of the particles are less than 100 micrometers in diameter. In another embodiment, not less than 95% of the particles are less than 500 micrometers in diameter, not more than 90% are less than 250 micrometers in diameter, not more than 60% are less than 180 micrometers in diameter, and not more than 30% are less than 125 micrometers. (Analyses performed using sieves according to the Sieve Test 2.9.12 Eur. Ph.—Alpine Air Jet Sieve.) The average particle size for the diclofenac powder is preferably about 150, 160, 170, 180, 190, 200, 210, 220, 230, or 240 micrometers, and can range between any two of the foregoing variables (i.e. from about 150 to about 230 micrometers, or from about 170 to about 220 micrometers).
As it will be clear from the examples, the immediate release formulations for oral use of the present invention containing from 10 to 60 mg of diclofenac in acid and/or salt form together with alkali metal bicarbonates or mixtures thereof in amounts of from 20 to 80% by weight based on the weight of diclofenac permit to generate in human patients an average Cmax of diclofenac comprised between 400 and 2500 ng/ml independently on the age, sex or weight of the patients themselves. In addition, the formulations according to the present invention yield average an tmax of Diclofenac in humans within 5-30 minutes of administration, generally 13-27, independently of the amount of diclofenac contained therein and also independently on the age, sex, weight of the patient.
Furthermore, the tmax of the formulations of the present invention show a coefficient of variation which is lower than the presently marketed formulations; this is evidently an extremely important result from the clinical point of view as it is now possible to have a therapeutic effect of diclofenac which is foreseeable, reproducible and independent of the sex, weight and health conditions of the patient. Thus, the presently claimed diclofenac-based formulations permit to achieve a higher Cmax in a shorter tmax and with a lower coefficient of variation when compared to the formulations available on the market, with therapeutic advantages which do not need to be commented.
Test Formulations: T1: Diclofenac potassium 50 mg film-coated tablets, alcohol granulation
Test Formulations: T1: Diclofenac potassium 25 mg film-coated tablets
Test Formulation: Diclofenac potassium 50 mg film-coated tablets
Reference Formulation: Diclofenac potassium, 50 mg film-coated tablets, Voltfast® by Novartis Pharma
Study design: Single dose, 2-way, crossover randomised on 26 healthy volunteers
Blood samples drawn: 0 (pre-dose), 10, 20, 30, 45, 60, 90 min, 2, 3, 4, 5, 6, 8, 10, 12 h
Assay: LC-MS-MS//LOQ 3.3 ng/ml
Test Formulations: Diclofenac potassium 12.5 mg film-coated tablets
Reference Formulation: Diclofenac potassium, 12.5 mg immediate release film-coated tablets, Voltaren Dolo® by Novartis Consumer Health
Study design: Single dose, 2-way, crossover randomised on 24 healthy volunteers
Blood samples drawn: 0 (pre-dose), 5, 10, 15, 20, 30, 45, 60, 75, 90 min, 2, 3, 4, 5, 6, 8, 12 h
Assay: LC-MS-MS//LOQ 0.2 ng/ml
A further comparative test was carried out on uncoated immediate release formulations T1 and T2, as reported in Example 1. A comparative bioavailabilty study was carried out on 6 healthy volunteers of both sexes in order to evaluate the in vivo results of the pharmacokinetic profiles of the present formulations if compared to those of a bioequivalent fast release formulation such as Voltaren Rapid® (50 mg of diclofenac potassium), by Novartis. The results, which are reported in
Uncoated diclofenac tablets containing 50 mg. of diclofenac potassium were prepared based on the formulations given in Table 9 below. Formulations were prepared using alcoholic granulation (Tablet C) and direct compression (Tablet B).
Stability tests were conducted in various blister packaging materials on the tablet cores (Tablet B and Tablet C), and on Tablet B tablets coated with an aqueous polymer coating suspension (Tablet BA) and an alcoholic polymer coating solution (Tablet BB). Stability testing was restricted to three different blister types. The properties of the forming and lidding films used in the three blister materials tested are as follows:
Samples were withdrawn at suitable intervals and subjected to testing for Diameter, Thickness, Hardness, Weight, Disintegration time in water (37° C.), Water content, Dissolution buffered pH 7.5 medium, and Assay. The measurements were performed on six tablet cores or coated tablets taken at random in all instances, and the average values were recorded. The results are given in Tables 10-15 below.
aAll values are average values determined on six units taken at random.
bMatrix tablets produced by direct compression of the mixture F11 with a rotary tablet machine.
cStability in blister 1 was interrupted after 3 months.
dMatrix tablets produced from the mixture F3 (alcoholic granulation) with a rotary tablet machine.
eStability of batch no. 990310C was interrupted after 3 months.
fErweka TBH 30 HD apparatus.
gDetermined according to Eur. Ph. (Karl Fischer semi-micro water determination).
hDetermined in water (37° C.) according to Eur. Ph.
iDetermined in buffered pH 7.5 medium according to Eur. Ph.
jDetermined by high performance liquid chromatography (HPLC).
Using the dissolution test procedure described in the European Pharmacopeia, the dissolution profiles for two tablets (Ex. 8a and 8b) having the composition set forth in Table 8 were generated. The only difference between the two tablets was the source of the diclofenac potassium. Dissolution profiles of 50 mg. diclofenac potassium tablets marketed as Voltaren Rapid and Voltfast were also generated, and graphs of the contrasting dissolution profiles were superimposed, to produce
Throughout this application, various publications are referenced. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art to which this invention pertains. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
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