WO2004047834A1

WO2004047834A1 - Formulation and manufacturing process of solubilized aceclofenac soft capsules

Info

Publication number: WO2004047834A1
Application number: PCT/KR2003/000533
Authority: WO
Inventors: Young-Sig Gil; Seok-Cheon Hong; Chang-Hun Yu; Dong-Hyun Cho; Hyun-Jong Shin
Original assignee: Korea United Pharm, Inc.
Priority date: 2002-11-23
Filing date: 2003-03-20
Publication date: 2004-06-10
Also published as: AU2003215942A1; KR100397349B1

Abstract

The present invention relates to a method for the solubilization of aceclofenac, wherein water-insoluble aceclofenac is added to a solvent mixture of polyethylene glycols, ethanolamines, basic amino acids such as arginine, Tween and glycerin, and also to a solubilized aceclofenac-containing liquid composition prepared therefrom. Furthermore, the present invention relates to a solubilized aceclofenac-containing soft capsule, which is prepared by mixing 1-30 parts by weight, based on the total weight of the contents of the soft capsule, of aceclofenac, 10-90 parts by weight of polyethylene glycols, 1-70 parts by weight of ethanolamines, 1-70 parts by weight of basic amino acids, 1-40 parts by weight of Tween and 2-15 parts by weight of glycerin at a certain temperature range so as to prepare a solubilized aceclofenac-containing liquid composition; and filling the solubilized aceclofenac-containing liquid composition in a gelatin soft capsule.

Description

FOURMULATION AND MANUFACTURING PROCESS OF SOLUBILIZED ACECLOFENAC SOFT CAPSULES

Technical Field

The present invention relates in general to a method for solubilizing aceclofenac in an aqueous soluble base, a solubilized composition prepared therefrom, and also a soft capsule formulation containing the solubilized composition. More particularly, the present invention relates to a method for solubilizing aceclofenac, which can completely solubilize aceclofenac in a mixed solution of polyethylene glycol, Tween, glycerin and the like such that the dissolution of aceclofenac can be greatly improved, and also to a soft capsule formulation containing this solubilized content.

Background Art

Aceclofenac ( (2- [ (2 , 6-dichlorophenyl) amino] phenylacetoxyacetic acid, which is a known compound represented by the following formula, a phenylacetic acid- based anti-inflammatory analgesic drug showing an excellent effect for chronic joint diseases, including rheumatoid arthritis, osteoarthrosis ankylosing spendylitis and toothache, as well as post-operation or post-delivery pain.

This drug shows an excellent treating effect in that it is easily penetrated into inflammatory tissues occurring in a joint and the like, and thus shows excellent action of inhibiting prostaglandin production, as compared to other anti-inflammatory analgesic drugs, including naproxen and dichlorofenac . On the other hand, this drug shows weak inhibition of normal prostaglandin production in a gastric mucosa to reduce gastroenteric trouble so that it is suitable for long-term application. Particularly, this drug is characteristic in that it inhibits the production of interleukin-1 causing the destruction of joint cartilage and accelerates the production of glycosaminoglycan found in joint cartilage, thereby preventing rheumatoid arthritis, osteoarthrosis and the like from being worse.

Aceclofenac (2- [ (2 , 6-dichlorophenyl) amino] phenylacetoxyacetic acid) has characteristics in that it is easily soluble in an organic solvent and difficultly soluble in water. Acelofenac is rapidly absorbed in the gastrointestinal tract upon oral administration, and then distributed in kidneys, vesica, liver, thyroid gland and the like at high concentration but distributed in eye, brain, and fat tissues at low concentration. Upon oral administration, aceclofenac shows an onset time of shorter than 30 minutes, a time to maximum blood concentration (T_ma_x) of about 1.5-2.5 hours, and a duration time of about 12 hours. Upon oral administration, 46-75% of the administered drug is present as aceclofenac at the time to maximum blood concentration (T_max) and widely metabolized after T_max. In this case, a main metabolite is 4- hydroxyaceclofenac, which also shows activity, and it is known that 4-hydroxydichlorofenac and indole derivatives are also observed as other metabolites. It is known that, upon oral administration, about 66.8% of aceclofenac is eliminated in feces and about 18% is eliminated in urine, and also aceclofenac has an elimination half-life of about 4 hours .

Aceclofenac showed acute toxicity in a dose-dependent manner. This acute toxicity was more sensitive in females than males, and showed gastrointestinal diseases. LD₅₀ of aceclofenac was 146.2 g/kg in females and 199.5 mg/kg in males. With respect to sub-acute toxicity, when administered to rats at a dose of 3 mg/kg/day, aceclofenac showed safety, and at a dose of 6 mg/kg/day, it showed a slight increase in spleen weight and a change in serum for only females and thus is believed to have tolerability. At a dose of 12 mg/kg/day, aceclofenac showed only general toxic symptoms, which are well known in a nonsteroidal inflammatory drug. Thus, aceclofenac is believed to be relatively safe. With respect to chronic toxicity, when administered to rats at a dose of 1.5 mg/kg/day, aceclofenac showed only a slight decrease in body weight and a slight change on [Ca⁺⁺] and inorganic salts in blood during 2 months of the end of an experiment, and at a dose of 3.6 mg/kg/day, it showed a change in body weight and blood chemical components from 2 months after administration, and caused ulcer formation and bleeding in jejunum and caecum. With respect to teratogenicity, when administered to females at 2.5, 5.0 and 10.0 mg/kg/day, aceclofenac had no effect on clinical symptoms, the viability of corpus luteum, and the ratio between implanted females and males of died or survived embryos. In the case of survived embryos, aceclofenac did not cause a significant change in injury of external appearance, teratogenicity, and organs. Thus, aceclofenac does not show teratogenicity in rats under the above conditions. Aceclofenac has the following clinical characteristics. 1) It inhibits the production of interleukin-1 causing the destruction of joint cartilage and accelerates the production of glycosaminoglycan found in joint cartilage, so that it is suitable for the prevention of rheumatoid arthritis and osteoarthrosis . 2) Aceclofenac has a reduced effect on normal prostaglandin production, in a gastric mucosa such that gastroentric trouble is minimized. 3) Aceclofenac is penetrated into an inflammatory site, such as a joint, at high concentration so that it has a powerful effect of inhibiting prostaglandin production in foci .

Aceclofenac showing this powerful effect of alleviating pain is currently developed and marketed in tablet form. However, a tablet among pharmaceutical formulations requires several processes in which the tablet must be first disintegrated upon oral administration, and the drug mixed with vehicles is absorbed only after it was dissolved in digestive fluid or body fluid. For this reason, onset time of the tablet will be necessarily delayed as compared to the case where pre-dissolved drugs, such as liquid formulations or soft capsules, are administered. Thus, the present inventions have conducted a study to develop a formulation, which can improve the shortcomings of the prior tablet and remove rejection against drugs. During this study, the present inventors have attempted to develop a soft capsule formulation containing solubilized aceclofenac, which can greatly improve the dissolution rate and thus in vivo absorption rate of aceclofenac by the solubilization of aceclofenac as in the present invention, so that a treating effect of aceclofenac can be further maximized.

Methods for formulating a drug into a soft capsule are broadly divided into two methods as follows. The first method is a generally known method wherein a drug is suspended in an oily base, such as vegatable oil, such as soybean oil, coconut oil, sunflower seed oil, sesame oil, perilla oil or olive oil, or middle chain triglyceride, using a suspending agent such as beewax. This method can delay the dissolution of the drug and thus must be carefully considered.

The second method is a method wherein a drug is solubilized or suspended in an aqueous soluble base, such as polyethylene glycol or propylene glycol .

However, when aceclofenac is formulated into the soft capsule formulation in order to increase the dissolution rate thereof, the first method in which aceclofenac is suspended in the oily base is difficult to achieve the desired dissolution rate. In the second method using the aqueous soluble base, a technique where aceclofenac is suspended in a base such as polyethylene glycol 400 improves the dissolution rate as compared to the method of suspending aceclofenac in the oily base, but is also difficult to achieve a significant increase in the dissolution rate. Korean Patent Application No. 1999- 0027950 discloses a method wherein polyethylene glycol, glycerin, and purified water are used to solubilize nitrendipine . However, this method is not recommendable since the soft capsule formulation can be softened or degraded by purified water. Moreover, US Patent No. 5,141,961 discloses an ethanol-containing liquid pharmaceutical composition in which ibuprofen is solubilized using ethanol, polyethylene glycol and polyvinyl pyrrolidone. US Patent No. 5,071,643 discloses a method of solubilizing ibuprofen using an ionizable solvent system comprising glycerin, polyethylene glycol, polyvinyl pyrrolidone and water, but is not recommendable since it can affect the softening and hardening of a soft capsule formulation. The composition disclosed in US Patent 5,141,961 is an ethanol-containing liquid pharmaceutical composition and thus has a problem in that its safety is reduced upon long-term storage, namely, its contents are precipitated due to a change in ethanol content, thereby reducing its bioavailability. Thus, a method of solubilizing a drug with minimized use of purified water or ethanol will allow the soft capsule formulation to be more effectively prepared.

Disclosure of Invention

Currently, aceclofenacs are mostly developed and marketed in tablet form. If a drug is a formulation, such as aceclofenac, which is difficultly soluble in water, the tablet will have low dissolution rate of the drug, and thus low in vivo absorption rate and bioavailability of the drug, so that it cannot show the sufficient expression of a drug effect. Accordingly, the present invention aims to develop a formulation showing the most rapid expression of a drug effect in patients by further improving the dissolution rate and in vivo absorption rate of the drug, as compared to the prior formulation as described above. For this purpose, a drug needs to be formulated into a soft capsule formulation, which shows high dissolution rate and in vivo absorption rate of the drug. Even if the drug is formulated into the soft capsule formulation, when a generally known method for the formulation of the drug wherein the drug are suspended in an oily base, such as vegetable oil, including soybean oil, coconut oil and wheat germ oil, mineral oil, or medium chain triglyceride (MCT) , with a suspending agent such as beewax, is used in the formulation of the drug, there is a problem in that it is difficult for the dissolution rate of the drug, such as aceclofenac, to be greatly improved.

Furthermore, as an improved method over the general method of formulating a soft capsule content as described above, there is a method wherein a hydrophilic liquid base, such as polyethylene glycols 300-600, which is known to be widely used for the preparation of a transparent soft capsule, is mixed with a hydrophilic semi-solid or solid material, such as polyethylene glycols 1500-20000, and a drug is suspended in the mixture. This method can somewhat improve the dissolution velocity and rate of the drug, but does not show a significant effect.

The present inventors have conducted a long-term study on a soft capsule formulation, and consequently found that if aceclofenac is added to polyethylene glycol 400, aqueous soluble bases and alkalifying agents, the solubility of aceclofenac can be greatly increased, thereby greatly improving the bioavailability of aceclofenac. Also, the present inventors designed a soft capsule formulation by a method of filling this mixture in a soft capsule so as to develop a formulation capable of greatly improving the dissolution rate of aceclofenac, thereby perfecting the present invention. Therefore, an object of the present invention is to provide a liquid composition containing solubilized aceclofenac, in which 1-30 parts by weight of aceclofenac is mixed with 10-90 parts by weight of polyethylene glycol, 1-70 parts by weight of ethanolamine, 1-70 parts by weight of basic amino acid, 1-40% parts by weight of Tween and 2- 15 parts by weight of glycerin.

Also, an another object of the present invention is to provide a soft capsule formulation containing a composition prepared by mixing and solubilizing 1-30 parts by weight, based on the total weight of the composition, of aceclofenac with 10-90 parts by weight of polyethylene glycol, 1-70 parts by weight of ethanolamine, 1-70 parts by weight of basic amino acid, 1-40 parts by weight of Tween and 2-15 parts by weight of glycerin. An still another object of the present invention is to provide a method for preparing an aceclofenac-containing soft capsule formulation, which comprises the steps of: mixing 10-90 parts by weight of polyethylene glycol, 1-70 parts by weight of ethanolamine, 1-70 parts by weight of basic amino acid, 1-40 parts by weight of Tween and 2-15 parts by weight of glycerin with each other at a temperature of 60-80 °C; adding and solubilizing 1-30 parts by weight of aceclofenac in the mixture; and filling the resulting liquid composition in a gelatin soft capsule. Best Mode for Carrying Out the Invention

In the present invention, aceclofenac as a pharmaceutically active substance could be solubilized at the amount of 1-40 parts by weight. In view of the expression of a drug effect, aceclofenac could be solubilized at the amount of 1-30 parts by weight such that its dissolution and content stabilities can be ensured. Thus, aceclofenac is preferably soulibilized at the amount of 1-30 parts by weight. As an agent for solubilizing aceclofenac, there is used polyethylene glycol, and preferably polyethylene glycol 300, 400, 500 and/or 600, and more preferably polyethylene glycol 400. In this case, polyethylene glycol is used at the amount of 10-90 parts by weight, and preferably 40-80 parts by weight.

Examples of ethanolamine that can be used in the present invention include monoethanolamine, diethanolamine and triethanolamine . Diethanolamine is used at the amount of 1-70 parts by weight, and preferably 1-30 parts by weight. Examples of basic amino acid that can be used in the present invention include L-arginine, L-histidine and L-lysine. Among these basic amino acids, L-arginine is preferably used at the amount of 1-70 parts by weight, and more preferably 1-50 parts by weight. Furthermore, Tween is used at the amount of 1-40 parts by weight, and preferably 5-8 parts by weight, and glycerin is used at the amount of 2-15 parts by weight, and preferably 5-13 parts by weight . These solvents are mixed with each other to prepare an aqueous soluble solvent system. If the respective solvents are used at a smaller amount than the lower limit of the content range, the solubilization of aceclofenac cannot be accomplished, whereas if they are used at a larger amount than the upper limit, the size of the resulting formulation will be increased, thereby reducing product quality.

In a more concrete method for preparing the aceclofenac-containing composition to be filled in the soft capsule, glycerin, ethanolamine, arginine, Tween and polyethylene 400 are first mixed with each other, after which the mixture is heated to a temperature of 60-80 °C and further mixed at this temperature. Next, aceclofenac is slowly added to the resulting mixture at 50 °C, and examined if it was dissolved. Then, the completely dissolved transparent mixture is slowly stirred while cooling to room temperature. After this, bubbles are removed with a vacuum pump, thereby obtaining a solubilized liquid composition.

The gelatin soft capsule used in the present invention, which is a soft-gel formulation containing gelatin and plastcizer, is prepared by a conventional preparing method. The soft capsule formulation containing the solubilized aceclofenac according to the present invention is molded using an automatic rotary filling machine according to a conventional filling method, and then subjected to drying and sorting processes, thereby obtaining a test product.

Furthermore, the soft capsule formulation prepared according ^' to the present invention has excellent dissolution and content stabilities. Thus, when this soft capsule formulation was measured for its stability for six months at room temperature and accelerated conditions, it showed little or no change in its content and property. Also, this formulation showed excellent aceclofenac dissolution rate as compared to a conventional aceclofenac tablet formulation. Accordingly, the present invention provides the soft capsule formulation having excellent dissolution rate and high stability.

The soft capsule formulation according to the present invention contains lOOmg aceclofenac per capsule so as to exhibit an anti-inflammatory analgesic effect and is administered at one capsule two times a day for adults.

The present invention will hereinafter be described in further detail by examples and comparative examples. It should however be borne in mind that the present invention is not limited to or by the examples.

Example 1 :

217g of polyethylene glycol 400, 37g of diethanolamine, 5g of arginine and 7g of Tween 20 are mixed with each other, warmed to 70 °C, and completely mixed at this temperature. Then, lOOg of aceclofenac is slowly added to the mixture at the same temperature and stirred. After the mixture became completely transparent, it is cooled to room temperature, and a bubble is removed using a vacuum pump, thereby obtaining 336g of a solubilized aceclofenac-containing composition to be filled in a soft capsule (see, Table 1) .

Table 1:

Example 2 : 217g of polyethylene glycol 400, 37g of diethanolamine, 5g of histidine and 7g of Tween 20 are mixed with each other, warmed to about 70 °C, and completely mixed at this temperature. Then, lOOg of aceclofenac is slowly added to the mixture at the same temperature and stirred. After the mixture became completely transparent, it is cooled to room temperature, and a bubble is removed using a vacuum pump, thereby obtaining 336g of a solubilized aceclofenac- containing composition to be filled in a soft capsule (see, Table 2) .

Table 2 :

Example 3 :

217g of polyethylene glycol 400, 37g of diethanolamine, 5g of L-lysine and 7g of Tween 20 are mixed with each other, warmed to 70 °C, and completely mixed at this temperature. Then, lOOg of aceclofenac is slowly added to the mixture at the same temperature and stirred. After the mixture became completely transparent, it is cooled to room temperature, and a bubble is removed using a vacuum pump, thereby obtaining 366g of a solubilized aceclofenac-containing composition to be filled in a soft capsule (see, Table 3) . Table 3

Example 4 :

217g of polyethylene glycol 400, 37g of diethanolamine, 5g of sodium hydrogen phosphate and 7g of Tween 20 are mixed with each other, warmed to 70 °C, and completely mixed at this temperature. Then, lOOg of aceclofenac is slowly added to the mixture at the same temperature and stirred. After the mixture became completely transparent, it is cooled to room temperature, and a bubble is removed using a vacuum pump, thereby obtaining 366g of a solubilized aceclofenac-containing composition to be filled in a soft capsule (see, Table 4) .

Table 4 :

Example 5 :

Preparation of content of soft capsule 246g of polyethylene glycol, 7g of diethanolamine and 7g of Tween 20 are mixed with each other, warmed to about 50 °C and further mixed at this temperature such that they are homogenized. lOOg of aceclofenac is added to the mixture at about 50 °C and stirred with a paddle stirrer at about 1200-2000 rpm while examining if the aceclofenac is dissolved. After aceclofenac was completely dissolved, the mixture is cooled to room temperature with slow stirring. A bubble is removed using a vacuum pump, thereby obtaining a composition to be filled in a soft capsule (see, Table 5) ,

Table 5 :

Preparation of coating of soft capsule

A soft capsule coating, which is used in the present invention, is prepared using a conventional soft capsule formulation containing gelatin and plasticizer in such a manner that the coating contains 167g gelatin, 68g glycerin, 0.5g methyl paraoxybenzoate, and 0.08g propyl paraoxybenzoate, per capsule (see, Table 6) . Table 6:

Preparation of soft capsule formulation

In preparing a soft capsule formulation containing solubilized aceclofenac, the liquid composition containing solubilized aceclofenac obtained by each of Examples is molded into an Oval 6 type using a conventional automatic rotary filling machine in such a manner that 100 mg aceclofenac is contained per capsule. The resulting capsule formulation is subjected to drying and sorting process, thereby obtaining a test product.

Comparative Example 1 :

In this example, aceclofenac is dissolved in middle chain triglyceride (MCT) using, as a dissolving or suspending agent, CremophorRH40 and beewax that are known to improve the dissolution of a drug. This gives an aceclofenac-containing composition (see, Table 7) .

Table 7:

Then, the formulation of a gelatin coating and the preparation of a soft capsule formulation containing the composition are carried out in the same manner as described above, thereby obtaining a sample whose dissolution rate is compared to those of Examples in the following Test Example.

Test Example 1: Test and evaluation of dissolution rate

In order to test and evaluate the dissolution rate of aceclofenac, the soft capsule formulations prepared by Examples 1-4, the soft capsule formulation prepared by Comparative Example 1, and a formulation commercially available under the trademark of Clanza tablet, were used. Results are given in Table 8 below.

A dissolution test of aceclofenac was carried out according to a dissolution test method of Clanza tablet, which is an aceclofenac-containing tablet formulation marketed in the name of this applicant. Namely, this dissolution test method was carried out according to the second dissolution method of Korea Pharmacopeia at a paddle rotating speed of 100 rpm in 900 mL of phosphate buffer (pH 7.8). As a sample solution, there was used a solution, which had been filtered through a 0.45 μm membrane filter. Meanwhile, for use as a standard solution, lOOmg of an aceclofenac standard was precisely weighed and dissolved in 900ml of phosphate buffer. These solutions were analyzed by liquid chromatography.

Amount of dissolved aceclofenac in sample solution = amount of standard solution (mg) x peak area of sample solution/peak area of standard solution

Table 8 : Results of dissolution test of aceclofenac formulation

Dissolution rate (%)

As evident from Table 8, the aceclofenac formulation, which was solubilized according to the present invention, is the soft capsule formulation having increased dissolution rate as compared to the prior formulation. Thus, the soft capsule formulation of the present invention has a characteristic in that it improves the dissolution rate and thus in vivo absorption rate of aceclofenac, thereby greatly improving a pharmacological effect of acceclofenac .

Test Example 2 : Stability test

The formulations according to Examples 1-5 and Comparative Example 1 were tested for their stability at room temperature and an accelerated condition of 40 °C for six months. Results are given in Table 9.

Table 9: Results of stability test of aceclofenac formulation

As evident from Table 9, the soft capsule formulation prepared according to the present invention did not show browning or precipitation, which occurred in the formulation of Comparative Example 1. Industrial Applicability

As described above, the present invention provides the solubilizing method of aceclofenac capable of greatly improving the dissolution rate of aceclofenac, in which aceclofenac is completely solubilized in a mixed solution of polyethylene glycol, basic amino acids, Tween, glycerin and various alkalifying agents. Also, the present invention provides the composition prepared by this solubilization method, and also the soft capsule formulation containing this composition. Furthermore, the present invention will contribute to the development of a new formulation, which shows an increase in dissolution rate and in vivo absorption rate of differently soluble drugs, which was not achieved by prior similar formulations.

Claims

What Is Claimed Is:

1. A liquid composition containing solubilized aceclofenac, wherein 1-30 parts by weight of aceclofenac is mixed with 10-90 parts by weight of polyethylene glycol, 1- 70 parts by weight of ethanolamine, 1-70 parts by weight of basic amino acid, 1-40 parts by weight of Tween and 2-15 parts by weight of glycerin under heating such that the aceclofenac is solubilized.

2. A soft capsule formulation containing aceclofenac, wherein an aceclofenac-containing liquid composition^' prepared by mixing and solubilizing 1-30 parts by weight, based on the total weight of the liquid composition, of aceclofenac with 10-90 parts by weight of polyethylene glycol, 1-70 parts by weight of ethanolamine, 1-70 parts by weight of basic amino acid, 1-40 parts by weight of Tween and 2-15 parts by weight of glycerin, is filled in a gelatin soft capsule.

3. The soft capsule formulation of Claim 2, wherein the polyethylene glycol is one or more selected from polyethylene glycols 300, 400, 500 and 600.

4. The soft capsule formulation of Claim 3, wherein the polyethylene glycol is the polyethylene glycol 400.

5. The soft capsule formulation of Claim 2, wherein the ethanolamine is one or more selected from monoethanolamine, diethanolamine and triethanolamine .

6. The soft capsule formulation of Claim 2, wherein the basic amino acid is one or more selected from L- arginine, L-histidine and L-lysine.

7. The soft capsule formulation of Claim 2, wherein the composition is transparent .

8. A method for preparing an aceclofenac-containing soft capsule formulation, which comprises the steps of: mixing 10-90 parts by weight of polyethylene glycol, 1-70 parts by weight of ethanolamine, 1-70 parts by weight of basic amino acid, 1-40 parts by weight of Tween and 2-15 parts by weight of glycerin with each other at a temperature of 60-80 °C; adding and solubilizing 1-30 parts by weight of aceclofenac in the mixture; and filling the resulting transparent liquid composition in a gelatin soft capsule.

9. The method of Claim 8, wherein the polyethylene glycol is one or more selected from polyethylene glycols

300, 400, 500 and 600.

10. The method of Claim 9, wherein the polyethylene glycol is the polyethylene glycol 400.

11. The method of Claim 8, wherein the ethanolamine is one or more selected from monoethanolamine, diethanolamine and triethanolamine .

12. The method of Claim 8, wherein the basic amino acid is one or more selected from L-arginine, L-histidine and L-lysine.

13. The method of Claim 8, wherein the composition is transparent .