LONG-LASTING COMPOSITION FOR RECTAL ADMINISTRATION

Abstract: There is provided a composition for rectal administration suitable for curing hemorrhoids or the like by which the concentration of a medicine in the affected tissue is increased and the potency of the medicine is expected to continue. A long active composition for rectal administration which comprises an acrylic acid polymer, a vasoconstrictor and a rectal tissue-curing agent.

Description: Technical Field This invention relates to a composition for rectal administration, more particularly to a composition for rectal administration suitable for local curing such as curing of hemorrhoids or the like which comprises an acrylic acid polymer, a vasoconstrictor and a rectal tissue-curing agent, and for which composition it is expected that the concentration of the above curing agent in the rectal tissue is increased and that the potency of the curing agent continues. Background Art It is known that conventional preparations for rectal administration such as a suppository and the like, when administered to an anorectal region, spread with time from the administered site to the upper region of the rectum because a base in the preparation is melted at the body temperature to become a liquid state. For the purpose of local curing such as curing of hemorrhoids or the like, the spreading of the preparation to the upper region of rectum results in a decrease of the amount of the preparation present in the vicinity of the affected region. Therefore, reports have been made on a preparation for rectal administration for the purpose of preventing the spread of the preparation in the rectum and allowing the preparation to remain in the vicinity of the affected region. For example, there is disclosed a preparation for rectal administration which has been enabled to remain in the vicinity of the affected region in rectum by incorporating a metal salt of polyacrylic acid in JP-A-54-26325, by incorporating a mixture of polyacrylic acid and polyvinylpyrrolidone in JP-A-6-40889 and by incorporating carboxyvinyl polymer in JP-A-63-280016 and JP-A-1-143825. Disclosure of Invention The present inventors have made various examinations on compositions for rectal administration and have consequently found that a preparation comprising as a composition, an acrylic acid polymer, a vasoconstrictor and a rectal tissue-curing agent not only can remain in the vicinity of the affected region in rectum but also can inhibit the above curing agent from diffusing from the rectal tissue, increase the concentration of the curing agent in the tissue and become a preparation for rectal administration whose potency continues, and have completed this invention. That is to say, this invention is a long active composition for rectal administration which comprises an acrylic acid polymer, a vasoconstrictor and a rectal tissue-curing agent. In this invention, the acrylic acid polymer is polyacrylic acid, a polyacrylic acid salt, a partially cross-linked polyacrylic acid or its salt. The average molecular weight thereof is 100,000 to 10,000,000 and the content of carboxyl group thereof is preferably 50 to 70%, more preferably 58 to 63%. The particle size is preferably 500 microns or less, more preferably 250 microns or less. As the partially cross-linked polyacrylic acid, there are mentioned, for example, carboxyvinyl polymer, carbomer and polycarbofil, and preferably carboxyvinyl polymer. As the salt of polyacrylic acid, there are mentioned alkali metal salts such as sodium salt, potassium salt and the like; alkaline earth metal salts such as calcium salt and the like; trivalent metal salts such as aluminum salt and the like; and ammonium salt. Preferable are potassium polyacrylate, sodium polyacrylate, calcium polyacrylate and ammonium polyacrylate. The amount of the acrylic acid polymer formulated is 0.1 to 20% by weight based on the total amount of the composition for rectal administration. Among the acrylic acid polymers, most preferable is carboxyvinyl polymer and the amount of the same formulated is 0.2 to 15% by weight, more preferably 1 to 10% by weight, based on the total amount of the composition for rectal administration. When the amount of the acrylic acid polymer formulated is small, the duration in rectum becomes poor and when the amount is large, the viscosity becomes high and the production of the preparation and filling with the preparation tend to become difficult. The vasoconstrictor means a medicine having a vasoconstrictive action, and there is mentioned, for example, tetrahydrozoline hydrochloride, naphazoline hydrochloride, phenylephrine hydrochloride, ephedrine hydrochloride or oxymetazoline hydrochloride. The amount of the vasoconstrictor formulated is 0.005 to 2.0% by weight based on the total amount of the composition for rectal administration. Among the vasoconstrictors, preferable are tetrahydrzoline hydrochloride, naphazoline hydrochloride or oxymetazoline hydrochloride, and the amount of the same formulated is 0.005 to 0.1% by weight based on the total amount of the composition for rectal administration. Among these vasoconstrictors, most preferable is tetrahydrozoline hydrochloride. As the rectal tissue-curing agent is, for example, a medicine which is used for curing hemorrhoids or rectal cancer, and there are mentioned, for example, a steroid preparation such as hydrocortisone, hydrocortisone acetate, prednisolone, prednisolone acetate, dexamethasone, dexamethasone acetate, diflucortolone valerate or hydrocortisone propionate butyrate; an anti-phlogistic such as indometacin, ketoprofen, diclofenac sodium, lysozyme chloride or glycyrrhetic acid; a local anesthetic such as ethyl aminobenzoate, lidocaine, lidocaine hydrochloride, dibucaine, dibucaine hydrochloride, procaine, procaine hydrochloride, meprylcaine hydrochloride or mepivacaine; an antineoplastic agent such as 5-fluorouracil or futraful; an astringent such as zinc oxide, tannic acid, albumin tannate or potassium aluminum sulfate; an antihistamine such as diphenhydramine, diphenhydramine hydrochloride or chlorpheniramine maleate; a wound healing accelerator such as allantoin or aluminum chlorohydroxyallantoinate; a microbicide such as chlorhexidine hydrochloride, cetrimide, dequalinium chloride and benzalkonium chloride; a sulfa drug such as sulfisomidine, sulfisomidine sodium, homosulfamine or sulfadiazine; vitamines such as cod liver oil, ergocal-ciferol, riboflavin, pyridoxine hydrochloride or tocopherol acetate; a refrigerant such as d-camphor, dl-camphor, l-menthol, dl-menthol, mentha oil or eucalyptus oil. The composition for rectal administration is used as a preparation for rectal administration, for example, as a suppository or an injection type ointment. When it is formed into a suppository, a base which is generally used as a suppository base is used. For example, an oleophilic base or a hydrophilic base can be used, and both of them may be used in admixture. As the oleophilic base, there are mentioned, for example, cacao butter, lanolin fat and hard fat. As the hard fat, there are mentioned, for example, Witepsol (manufactured by Hüls), Saposyer (manufactured by Gattefosse), Isocacao (manufactured by Kao) and Pharma sol (manufactured by NOF). As the hydrophilic base, for example, Macrogol is mentioned. The injection type ointment is used in any form of an oily ointment, a cream or a gel. In this case, as the base, there is used a conventionally used base. For example, an oily base, a water-soluble base or a mixture thereof is used depending upon the form of the oily ointment, cream or gel. As the base used as the oily base, there are mentioned, for example, oils and fats, fatty acids, higher alcohols and fatty acid triglycerides. As the oils and fats, there are mentioned, for example, olive oil, soybean oil, jojoba oil, rape seed oil, peanut oil, castor oil, mentha oil, coconut oil, cacao oil, palm oil, sesame oil, camellia oil, corn oil, hydrogenated oil, Japan wax, carnauba wax, lanolin oil, bees wax, squalane, squalene, beef tallow, lard, egg yolk oil, spermaceti, fluid paraffin, paraffin and vaseline. As the fatty acids, there are mentioned, for example, oleic acid, palmitic acid and stearic acid. As the higher alcohols, there are mentioned, for example, cetanol and stearyl alcohol. As the fatty acid triglycerides, for example, Panasate (manufactured by NOF) is mentioned. As the base used as the water-soluble base, there are mentioned, for example, glycerine and propylene glycol. Moreover, if necessary, surface active agents and additives can be added. Any surface active agent such as anionic, cationic, nonionic or amphoteric surfactant can be used. There are mentioned, for example, sorbitan fatty acid esters, glycerine fatty acid esters, decaglin, polysorbate, polyoxyethylene hydrogenated castor oil, polyethylene glycol fatty acid esters, polyoxyethylene alkyl ethers, alkylsulfuric acid salts, alkylammonium salts, N-acylamino acid salts or lecithin. As the alkylsulfuric acid salts, for example, sodium dodecylsulfate is mentioned. As the alkylammonium salts, for example, stearyltrimethylammonium chloride is mentioned. As additives, there are mentioned, for example, an antiseptic, an inorganic oxide, a gelling agent, an antioxidant and a pH-regulator. As the antiseptic, there are mentioned, for example, alkyl polyoxybenzoates, sorbic acid or chlorhexidine gluconate. As the inorganic oxide, there are mentioned, for example, light anhydrous silicic acid and titanium oxide. As the gelling agent, for example, dextrin fatty acid esters are mentioned. As the antioxidant, for example, dibutylhydroxytoluene is mentioned. As the pH-regulator, there are mentioned, for example, citric acid and tartaric acid. The composition for rectal administration of this invention can be prepared by heating a base which is a soluble component to melt the same, thereafter mixing therewith an acrylic acid polymer, a vasoconstrictor and a rectal tissue-curing agent, and, if necessary, dispersing or dissolving other compounding agents in the base and then cooling them with stirring. Industrial Applicability The composition for rectal administration of this invention comprises an acrylic acid polymer, a vasoconstrictor and a rectal tissue-curing agent, by which the durability of the above curing agent is enhanced; has a superior curing and improving effect on diseases for which local action is expected, such as hemorrhoids and the like; and is useful as a preparation for rectal administration. Best Mode for Carrying Out the Invention Examples and Test Examples are shown below to explain this invention in detail. Example 1 (Prescription) Tetrahydrozoline hydrochloride 1 g Lidocaine 60 g Hydrocortisone acetate 5 g Allantoin 20 g Tocopherol acetate 60 g Light anhydrous silicic acid 20 g Carboxyvinyl polymer 75 g Witepsol W35 1,409 g (Production process) In a suppository base (Witepsol W35) which was heated and melted (50°C-70°C) were dispersed successively the other components with stirring and they were cooled to about 40°C, after which a suppository container was filled therewith, further cooled and shaped to obtain a suppository. Example 2 (Prescription) Phenylephrine hydrochloride 5 g Dibucaine 10 g Hydrocortisone acetate 5 g Zinc oxide 100 g Light anhydrous silicic acid 30 g Carboxyvinyl polymer 150 g Witepsol H15 1,450 g (Production process) A suppository was obtained in the same manner as in Example 1. Example 3 (Prescription) Naphazoline hydrochloride 1 g Lidocaine 60 g Prednisolone acetate 1 g Allantoin 20 g Tocopherol acetate 60 g Carboxyvinyl polymer 80 g Witepsol H15 1,528 g (Production process) A suppository was obtained in the same manner as in Example 1. Example 4 (Prescription) Oxymetazoline hydrochloride 1 g Lidocaine 50 g Hydrocortisone acetate 5 g Diphenhydramine hydrochloride 5 g Zinc oxide 100 g Polycarbofil calcium 100 g Pharma sol B115 1,539 g (Production process) A suppository was obtained in the same manner as in Example 1. Example 5 (Prescription) Oxymetazoline hydrochloride 1 g Lidocaine hydrochloride 60 g Allantoin 20 g Chlorpheniramine maleate 4 g Polycarbofil 75 g Light anhydrous silicic acid 20 g Pharma sol B115 1,520 g (Production process) A suppository was obtained in the same manner as in Example 1. Example 6 (Prescription) Tetrahydrozoline hydrochloride 1 g 5-Fluorouracil 100 g Carboxyvinyl polymer 75 g Light anhydrous silicic acid 24 g Pharma sol B115 1,200 g (Production process) A suppository was obtained in the same manner as in Example 1. Example 7 (Prescription) Tetrahydrozoline hydrochloride 0.05 g Lidocaine 3 g Hydrocortisone acetate 0.5 g Allantoin 1 g Carboxyvinyl polymer 3 g Liquid paraffin 82.45 g Dextrin fatty acid ester 10 g (Production process) An ointment base (liquid paraffin and dextrin fatty acid ester) heated and melted (70°C-90°C) was cooled to about 60°C and thereafter mixed with the other components with stirring to obtain an injection type ointment. Example 8 (Prescription) Naphazoline hydrochloride 0.05 g Lidocaine 3g Prednisolone acetate 0.1 g Allantoin 1 g Carboxyvinyl polymer 3 g White vaseline 92.85 g (Production process) An ointment base (vaseline) heated and melted (70°C-90°C) was mixed with the other components with stirring and thereafter the mixture was cooled to about 40°C to obtain an injection type ointment. Comparative Example 1 In the same manner as in Example 1, the production was conducted using the same prescription as in Example 1, except that the tetrahydrozoline hydrochloride was omitted and replaced with a suppository base (Witepsol W35) in an amount equal thereto. Comparative Example 2 In the same manner as in Example 1, the production was conducted using the same prescription as in Example 1, except that the carboxyvinyl polymer was omitted and replaced with an ointment base (Witepsol W35) in an amount equal thereto. Comparative Example 3 In the same manner as in Example 1, the production was conducted using the same prescription as in Example 1, except that the tetrahydrozoline hydrochloride and the carboxyvinyl polymer were omitted and replaced with a suppository base (Witepsol W35) in an amount equal thereto. Test Example 1: Determination of amount of drug in rectal tissue (Specimen) The suppository in Example 1 was used as a specimen. As control specimens, the suppositories in Comparative Examples 1 to 3 were used. (Test method) As the test method, the durability-in-rectum test in "Clinical Report", Vol. 42, No. 8, pages 1618-1626 (1993) was referred to. After fasting for 48 hours, to each of male Japanese white house rabbits (body weight: 2.5-3.0 kg), which were arbitrarily divided to groups each consisting of 5 rabbits, was administered the specimen or control specimen, and immediately the anal region was closed with Aronalpha to prevent the suppository from leaking. After the lapse of the given period of time, the rectum was enucleated and sufficiently washed with physiological saline, after which a rectal tissue of a section of 10 cm from the anal region was taken. The tissue taken was homogenated in 20 ml of purified water, and the drug was extracted from 2 ml thereof with 10 ml of dichloromethane, after which 8 ml thereof was evaporated to dryness. Thereto was added 1 ml of methanol to well dissolve the residue therein to prepare a sample solution, and this sample solution was subjected to high-performance liquid chromatography (HPLC) to determine the amounts of lidocaine and hydrocortisone acetate contained in 1 g of the affected tissue in the rectum. The enucleation of rectum was conducted after 30 minutes, one hour, three hours and six hours from the administration. (Result) When the specimen was compared with the control specimen, such a result was obtained that the former was larger in the amount of medicine in the rectal tissue than the latter. The results of the determination of the amount of lidocaine in the rectal tissue are shown in Fig. 1 and the results of the determination of the amount of hydrocortisone acetate are shown in Fig. 2. Test Example 2: Edema inhibition test (Specimen) The suppository of Example 1 was used as a specimen. As control specimens, the suppositories in Comparative Examples 1 and 3 were used. (Test method) The test method was in accordance with "Basic and Clinical Report", 27 (6), pages 2053-2062 (1993). After fasting for 24 hours, into the anal regions of male Wister rats (body weight: 150-170 g) which were arbitrarily divided to groups each consisting of 12 rats was inserted a swab impregnated with 0.16 ml of a prophlogistic agent (6% croton oil solution in ether : distilled water : pyridine : ether = 10 : 1 : 4 : 5) for 10 seconds to cause inflammation and immediately the specimen or the control specimen (in each case, the diameter was 3 mm and the length was 10 mm per 100 g of weight) was administered to each of the rats. After the administration of the suppository, the anal region was closed with a clip to prevent the suppository from leaking. After the lapse of six hours, the rectum was enucleated and an affected rectal tissue of a section of 5-20 mm from the anal region was taken. The wet weight thereof was measured and the rectal anal coefficient (RAC) was calculated and used as an index of the degree of edema. Moreover, the edema inhibition percentage was calculated from the mean value of RAC obtained. RAC and edema inhibition percentage were calculated according to the following calculation equation: RAC = Wet weight of rectal anal region (g) Body weight (g) x 1000 Edema inhibition percentage (%) [1 - (RAC of suppository administered group - RAC of untreated administered group)/(RAC of prophlogistic control material administered group - RAC of untreated control group)] x 100 (Result) When the specimen was compared with the control specimen, such a result was obtained that the former was at least 2 times higher in edema inhibition percentage than the latter. The results thereof are shown in Table 1. Brief Description of Drawings Fig. 1 is a graph showing the results of determination of the amount of lidocaine in 1 g of rectal tissue of a section of 10 cm from the anal region. Fig. 2 is a graph showing the results of determination of the amount of hydrocortisone acetate in 1 g of rectal tissue of a section of 10 cm from the anal region.

Claims: A long active composition for rectal administration which comprises an acrylic acid polymer, a vasoconstrictor and a rectal tissue-curing agent. The composition for rectal administration according to Claim 1, wherein the acrylic acid polymer is carboxyvinyl polymer. The composition for rectal administration according to Claim 1, wherein the vasoconstrictor is one or at least two members of tetrahydrozoline hydrochloride, naphazoline hydrochloride and oxymetazoline hydrochloride. A long active suppository which comprises an acrylic acid polymer, a vasoconstrictor and a rectal tissue-curing agent.

Inventors: FUJIMORI TOMOKO, KONDO OSAMU, TANAKA SHIGEO, URUSHIZAKI FUMIO, FUJIMORI, TOMOKO, KONDO, OSAMU, TANAKA, SHIGEO, URUSHIZAKI, FUMIO
Applicants: TAISHO PHARMA CO LTD, TAISHO PHARMACEUTICAL CO. LTD
Application year: 1996
Main classification: A61K9
IPC codes: A61K45, A61K9, A61K47