COMPOSITION FOR ORAL CAVITY

Abstract: A compsn. contg. mutanase for filling oral cavities contains, as surfactants, N-acylsarcosine salt or N-acyl-L-glutamic acid salt and one or more of the following: polyoxyethylene sorbitol fatty acid ester, polyoxyethylene glycerol fatty acid ester, polyoxyethylene alkyl ether, a poly oxyethylene lanolin deriv. polyoxyethylene nonylphenyl/formaldehyde concentrate, polyoxyethylene/polyoxypropylene block copolymer, polyoxyethylene hardened caster oil, polyoxyethylene caster oil, polyethylene glycol fatty ester. The amt. of N-acylsarcosine salt is 300 times more than the amt. of mutanase and is 0.01-3 wt.% of the total compsn. The amt. of N-acyl-L-glutamic acid salt is 3000 times more than the amt. of mutanase and is 0.01-3 wt.% of the total compsn.

Description: The present invention relates to compositions for the oral cavity, such as dentifrice, dental rinse, mouthwash, dental paste or denture cleanser, wherein mutanase (which is a pharmacologically active agent for preventing dental caries) is stably formulated. Heretofore, as one of the mechanisms for developing dental caries, it has been pointed out that Streptococcus mutans (which is an etiogenic bacterium of dental caries) produces a water-insoluble and adhesive glucan having α-1,3-glucoside bond (mutan) from sucrose, strongly adheres to the surfaces of teeth to produce lactic acid thereon, and results in decalcification of teeth (Clinical Bacteriology, Vol. 1, page 24, 1974). Mutanase is an enzyme which breaks an α -1,3-glucoside bond of the glucan produced by Streptococcus mutans , and a trial to prevent dental caries has been made by utilizing the activity of the enzyme to decompose the glucan to inhibit adhesion of Streptococcus mutans to the surfaces of teeth (Journal of Dental Research, Vol. 5, supplement, page 394, 1972). Mutanase used therein is derived from Trichoderma harzianum . However, in addition to this, the enzyme as derived from bacteria belonging to the genus Flavobacterium (JP-B-52/038113) and Pseudomonas (JP-B-56/001070) has also been reported. Further, to formulate mutanase in dentifrices has been proposed (JP-B-55/050006 and JP-B-57/036890) and it is accepted that mutanase is useful for preventing dental caries. However, mutanase is extremely unstable in the presence of water and surfactant, and is labilized by alterations in pH. Therefore its enzymatic activity is liable to be lost. On the other hand, surfactant is generally an essential ingredient as a foaming agent, dispersant and/or detergent in an oral composition and, therefore, it is very difficult to formulate mutanase in such a composition. It has however been proposed that mutanase be stably formulated in an oral composition by using N-acyl sarcosinate (JP-A-59/152314) or a combination of N-acyl sarcosinate with a sucrose fatty acid ester (JP-A-59/152315). Our studies have included adding a nonionic surfactant (as a foaming auxiliary) to an N-acyl sarcosinate (which shows "juice effect" and has excellent feeling of use)to obtain an oral composition having excellent feeling of use, foaming properties and stability. As a result, it has been found that, by using certain specific nonionic surfactants, the stabilization of mutanase can be obtained in the same degree as or more improved degree than that obtained by the prior art combination of N-acyl sarcosinate with a sucrose fatty acid ester. However, N-acyl sarcosinate may cause detachment of oral mucosa depending on the amount formulated; the amount thereof in a dentifrice is limited to not more than 0.5% by weight and therefore the use thereof is extremely limited. We find that mutanase can be stabilized by using an N-acyl-L-glutamate instead of an N-acyl sarcosinate, in combination with the specific nonionic surfactant. The object of the invention is a novel Formulation of an oral composition containing mutanase relatively stably. The present invention is characterized in that, in an oral composition containing mutanase, N-acyl-L-glutamate is formulated as a surfactant together with one or more nonionic surfactants selected from: polyoxyethylene sorbitol fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene lanolin derivative, polyoxyethylene nonyl phenyl formaldehyde condensation product, polyoxyethylene-polyoxypropylene block copolymer, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene hydrogenated castor oil, polyoxyethylene castor oil and polyethylene glycol fatty acid ester. We have Found that mutanase so formulated in an oral composition can maintain sufficient enzymatic activity for a long period of time, and excellent effect for preventing dental caries can be elicited. The ratio of N-acyl-L-glutamate to the nonionic surfactant is not more than 9:1. The N-acyl-L-glutamate to be used is represented by the formula: M' is a salt-forming group. R is an alkyl group, preferably having 11 to 17 carbon atoms. RCO is accordingly a fatty acid residue. As varieties of fatty acid, there are coconut oil fatty acid, lauric acid, stearic acid (hydrogenated tallow), distilled coconut oil fatty acid and mixed fatty acids (hydrogenated tallow an coconut oil). As the salt forming group, monosodium, triethanolamine and disodium are preferable in view of availability. Typical examples of the N-acyl-L-glutamates include monosodium N-lauroyl-L-glutamate, monosodium N-coconut oil fatty acid acyl-L-glutamate, monotriethanolamine N-coconut oil fatty acid acyl-L-glutamate and monosodium N-stearoyl-L-glutamate. Usually, the N-acyl-L-glutamate is formulated in an amount of not more than 3000-fold based on the amount of mutanase to be formulated and in an amount of 0.01 to 3% by weight based on the total weight of the composition. As the polyoxyethylene (POE) sorbitol fatty acid ester to be used, there are those wherein the addition molar number of ethylene oxide is 5 to 60 and the number of carbon atoms of the fatty acid is 12 to 18, typically, POE (60 mol) sorbitol tetraoleate, POE (60 mol) sorbitol tetrastearate and POE (6 mol) sorbitol monolaurate. As the polyoxyethylene glycerin fatty acid ester to be used, there are those wherein the addition molar number of ethylene oxide is 5 to 20 and the number of carbon atoms of the fatty acid is 8 to 18, typically, POE (15 mol) glyceryl monooleate and POE (15 mol) glyceryl monostearate. As the polyoxyethylene alkyl ether, there are those wherein the addition molar number of ethylene oxide is 2 to 50 and the number of carbon atoms of the alkyl is 12 to 22, typically, POE (9 mol) lauryl ether, POE (15 mol) cetyl ether and POE (10 mol) oleyl ether. As the polyoxyethylene lanolin derivative, there are those wherein the addition molar number of ethylene oxide is 1 to 100, typically, POE (30 mol) lanolin and POE (40 mol) lanolin alcohol. As the polyoxyethylene nonyl phenyl formaldehyde condensate, there are those wherein the addition molar number of ethylene oxide is 1 to 50, typically, POE (20 mol) nonyl phenyl formaldehyde condensate. As the polyoxyethylene (POE)-polyoxypropylene (POP) block copolymer, there are those wherein the average polymerization degree of ethylene oxide is 190 to 260 and the average polymerization degree of propylene oxide is 50 to 70, typically, POE (196 mol) POP (67 mol) block copolymer. As the polyoxyethylene sorbitan fatty acid ester, there are those wherein the addition molar number of ethylene oxide is 5 to 30 and the number of carbon atoms of fatty acid is 12 to 18, typically, POE (20 mol) sorbitan monostearate and POE (20 mol) sorbitan monooleate. As the polyoxyethylene hydrogenated castor oil, there are those wherein the degree of polymerization of ethylene oxide is 5 to 100, typically, POE (50 mol) hydrogenated castor oil, POE (60 mol) hydrogenated castor oil and POE (80 mol) hydrogenated castor oil. As the polyoxyethylene castor oil, there are those wherein the degree of polymerization of ethylene oxide is 3 to 70, typically, POE (60 mol) castor oil and POE (50 mol) castor oil. As the polyethylene-glycol fatty acid ester, there are those wherein the molecular weight of polyethylene glycol is 40 to 2800 and the number of carbon atoms of the fatty acid is 12 to 18, typically, POE (40 mol) monostearate and POE (45 mol) monostearate. These nonionic surfactants can be used alone or in combination thereof. These nonionic surfactants are formulated in an amount such that the weight ratio of N-acyl-L-glutamate to the nonionic surfactant is not more than 9 : 1 (in the direction of decrease in the amount of the N-acyl-L-glutamate) in view of stabilization of mutanase, and the amount of the nonionic surfactant is preferably not more than 3% by weight based on the total weight of the composition. Further, when the stability of the system of the composition is taken into consideration, the total amount of N-acyl-L-glutamate and nonionic surfactant is preferably not more than 5% by weight. Any mutanase having α-1,3-glucosidase activity can be used regardless of its microbial origin. Examples thereof which can usually be available include those obtained by cultivating mutanase-producing bacteria such as Trichoderma harzianum OMZ779, Cladosporium reginne QM7998, Streptomyces velensis , Aspergillus nidulans , Flavobacterium sp. or Pseudomonas sp. in a culture medium containing normal nutrients or a culture medium wherein α-1,3-glucan is further added in addition to normal nutrients, or those obtained by gene-manipulating mutanase-producing bacteria and fractionating the resulting supernatant of the culture solution containing mutanase by a salting-out method, adsorption method, or solvent fractionation method. In general, although mutanase slightly varies in properties depending upon a particular kind of producer, usually, it is characterized in that the optimum pH thereof is on the acidic side and the activity thereof is to solubilize mutan by decomposiiton to release reducing sugars. In the present invention, usually, the desirable effect for preventing dental caries can be obtained by formulating 1,000 to 1,000,000 units/g of mutanase in an amount of 0.001 to 10% by weight based on the total weight of the composition. One unit of mutanase is defined as the amount of the enzyme for decomposition of mutan, in 0.1 M acetic acid buffer solution (pH 5.7) at 40°C, to release 1 µM of reducing sugars as glucose per minute. The composition for the oral cavity of the present invention may be prepared in the form of dentifrice, dental rinse, mouthwash, paste, or denture cleanser, according to a conventional method. Other ingredients are not specifically limited and they may be any ingredients which can be used in this kind of compositions. For example in the case of toothpaste, polishing agents, binders, humectants, sweeteners, flavors, preservatives and other pharmacologically active agents can appropriately be formulated. Next, the results of tests for stabilization if mutanase by using N-acyl-L-glutamate in combination with nonionic surfactant are illustrated. I. Mutanase (17 mg, 6,500 units/g) derived from Pseudomonas sp. strain (FERM P-4273) was dissolved in 0.1 M acetate buffer solution (500 ml, pH 5.7) to obtain an enzyme solution. The enzyme solution (10 ml) was admixed with each solution (10 ml) of various surfactants as shown in Table 1. The mixture was allowed to stand at 25°C in a water bath for 3 hours and then enzyme activity in the mixture was determined. By taking the initial mutanase activity in a reaction system containing no surfactant as 100%, relative ratio of mutanase activity in a reation system containing the surfactant was determined. The results are shown in Table 1. As shown in Table 1, when the ratio of mutanase to monosodium N-lauroyl-L-glutamate was 1 : 300 and the ratio of mutanase to various nonionic surfactants was 1 : 300, namely, when monosodium N-lauroyl-L-glutamate and the nonionic surfactant were mixed together in the ratio of 1 : 1 and allowed to stand with mutanase, the stability of mutanase was specifically improved by using, among the nonionic surfactants, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene lanolin derivative, polyoxyethylene nonyl phenyl formaldehyde condensate, polyoxyethylene-polyoxypropylene block copolymer, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene hydrogenated castor oil, polyoxyethylene castor oil, polyethylene glycol fatty acid ester or polyoxyethylene alkyl ether. II. Next, according to the same manner as described in Table 1, the test was carried out by using N-acyl-L-glutamate having different fatty acids and salts and polyoxyethylene alkyl ether and polyoxyethylene sorbitan fatty acid ester (which showed particularly excellent stabilization among the nonionic surfactants) and by varying the ratio of the anionic surfactant to the nonionic surfactant as well as the ratio of the enzyme to the anionic and nonionic surfactants. The results are shown in Table 2. As shown in Table 2, the effect for stabilization of mutanase was not changed by varying the fatty acid of N-acyl-L-glutamate and by converting the salt portion thereof. In the results of the test carried out by adjusting the ratio of N-acyl-L-glutamate to nonionic surfactant, stabilization of mutanase is observed when the ratio of the N-acyl-L-glutamate to the nonionic surfactant is not more than 9 : 1 (in the direction of decrease in the amount of the N-acyl-L-glutamate), and mutanase activity is inhibited when the amount of N-acyl-L-glutamate is further increased. III. Next, a test was carried out by using the ratio which showed high stabilization in a combination system of the N-acyl-L-glutamate and polyoxyethylene sorbitan fatty acid ester, namely, the ratio of the anionic surfactant to the nonionic surfactant of 5 : 1, and varying the ratio to enzyme. As a result, as shown in Table 3, it was recognized that mutanase was stabilized when the ratio of the anionic surfactant to the nonionic surfactant was 5 : 1 and the ratio of enzyme to the anionic surfactant was 1 : 3000, the amount of the anionic surfactant being not more than 3% by weight of the total weight of the composition. The following are examples of formulations embodying the invention. Example 1 According to the following formulation, a toothpaste was prepared by a conventional method. Example 2 According to the following formulation, a toothpaste was prepared by a conventional method. Example 3 According to the following formulation, a mouthwash was prepared by a conventional method. Example 4 According to the following formulation, a denture cleanser was prepared by a conventional method.

Claims: An oral composition comprising (a) mutanase; (b) N-acyl-L-glutamate surfactant, and (c) one or more nonionic surfactants selected from: polyoxyethylene sorbitol fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene lanolin derivative, polyoxyethylene nonyl phenyl formaldehyde condensate, polyoxyethylene-polyoxypropylene block copolymer, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene hydrogenated castor oil, polyoxyethylene castor oil and polyethylene glycol fatty acid ester; the ratio of N-acyl-L-glutamate to the nonionic surfactant(s) being not more than 9:1. A composition according to claim 1 in which the amount of N-acyl-L-glutamate is not more than 3,000 times the amount of mutanase. A composition according to claim 1 or claim 2 in which the N-acyl-L-glutamate constitutes from 0.01 to 3wt% of the total composition. A composition according to any one of the preceding claims in which the total amount of N-acyl-L-glutamate and nonionic surfactant(s) is not more than 5wt% of the total composition. A composition according to any one of the preceding claims in which the nonionic surfactant constitutes not more than 3wt% of the total composition. A composition according to any one of the preceding claims in which the acyl of the N-acyl-L-glutamate is C₇₋₁₁ acyl. A composition according to any one of the preceding claims in which the mutanase is formulated at 1,000 to 1,000,000 units/g, to constitute 0.001 to 10wt% of the total composition. A composition according to any one of the preceding claims which is a dentifrice, dental rinse, mouthwash, paste or denture cleanser.

Inventors: OHTSUKI, HIDEHIKO, OZAWA, SATOKO, TANII, SAYURI
Applicants: SUNSTAR KABUSHIKI KAISHA
Application year: 1989
Main classification: A61K7
IPC codes: A61Q11, A61K8