MXPA97001019A - Adhesive composition improved for post denture - Google Patents

Abstract

The present invention relates to a denture adhesive composition containing a denture adhesive and a pharmacologically acceptable carrier, wherein the denture adhesive is a salt of a maleic acid or anhydride copolymer and an alkyl vinyl ether of 1 to 5 atoms of carbon, which has a specific viscosity of at least 4.0. The denture adhesive composition is used to adhere a denture to the mucosa or

Description

IMPROVED ADHESIVE COMPOSITION FOR POSTZA DENTURE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to adhesives, and in particular to adhesives for dentures, and to methods for making and using those adhesives. 2. Description of the Related Art Dentures are usually secured to the mouth using creams or powders that have adhesive properties. These adhesive denture compositions serve both to adhere the dentures to the gums and to provide a cushion and seal between the gums and the dentures and allow a comfortable fit. In addition, it is required that denture adhesives have acceptable organoleptic qualities. They also need to be strong enough so that with a single application of adhesive it is sufficient for an all-day use and the removal of the dentures at the end of the day, for cleaning or others, is not prevented or prevented. This last requirement has received more importance in recent years as the number of hours of continuous wear considered to constitute a "full day" has increased. P1051-97 MX The technical literature reveals a wide variety of adhesive materials for dentures. However, the denture adhesives currently on the market are based on alkyl vinyl ether / acid or maleic anhydride copolymers. This class of adhesives is designated as a potential denture adhesive in the document by Germann et al., United States Patent No. 3,003,988, which was issued more than 30 years ago. This patent discloses synthetic materials, water-sensitized but insoluble therein, comprising mixed partial salts of vinyl ether-lower alkyl-maleic anhydride copolymers to stabilize dentures. The salts mentioned in the patent are a mixture of (a) calcium and (b) alkalies including sodium, potassium and quaternary ammonium compounds, in a molar ratio of 1: 1 to 5: 1. The calcium and alkali materials are added to the copolymer to form a mixed salt. The use of this class of materials has been described in a variety of other patents. Examples include U.S. Patent Nos. 4,989,391, 5,037,924, 5,093,387, 4,980,391 and 4,373,036 European Published Patent Application No. 406,643 and WO 93/10988. These polymers and their salts have not proven to be totally effective in securing dentures P1051-97 MX as desired, particularly when the user of the denture consumes hot liquids. Additionally, it has been found that they are susceptible to "wash off", a term that refers to the erosion of the adhesive from the bottom of the denture, during use. As a result, the formulations have provided less than 12 hours of clamping power that users of the dentures have begun to request. In order to improve the adhesive and cohesive properties further, one approach that has been seen is to manipulate the salt form of the copolymer. Examples can be found in WO 92/22280, WO 92/10988, WO 92/10987 and U.S. Patent No. 4,758,630 and 5,073,604. Another approach has been to employ an adhesion adjuvant in the formulation or to convert the copolymer into a terpolymer, and examples of these approaches can be found in U.S. Patent Nos. 3,736,274, 5,037,924 and 5,093,387. Despite efforts to improve the properties of polymers of the maleic anhydride / alkyl vinyl ether type and their salts, these formulations do not provide the total degree of adhesion desired, nor the cohesion and resistance to washout by the lower part of the denture. The copolymer can be made in a variety of P1051-97 MX molecular weights and a suitable value is selected depending on the use for which it is to be used. It is generally recognized that the alkyl vinyl ether and maleic anhydride copolymer must have a high appropriate molecular weight, so that it is suitable for use as a denture adhesive. A minimum molecular weight is frequently indicated in a form corresponding to a specific viscosity of about 1.2 when measured in a 1% w / v solution in methyl ethyl ketone at 25 ° C. It is very rarely considered important how much above that value can rise in molecular weight and the description in WO / 92/10888 is a good example of this. U.S. Patent No. 4,373,036 is a rare exception as it indicates that the specific viscosity may be from about 1.5 to 3.5. The little consideration that has been given to the molecular weight can be understood both in a theoretical and experimental sense. As the molecular weight increases, the solubility of the polymer decreases. The polymer develops its adhesive strength when it is hydrated by the moisture of the individual's saliva and a decrease in solubility would make the polymer more difficult to hydrate. Consequently, it is expected that as the molecular weight increases the solubility would decrease, to the point of P1051-97 MX that the polymer could no longer function properly as an adhesive. As an example, it has been observed that a copolymer having a specific viscosity of about 3.5 does not have any statistically significant adhesive properties compared to those of a copolymer having a specific viscosity of about 2.6. As it is more difficult to produce the higher molecular weight polymer, there is no need to do so. In view of these considerations, it is not surprising that attempts to improve the denture adhesive compositions have ignored the molecular weight of the polymer. Surprisingly, it has now been found that when the molecular weight is sufficiently high it is possible to obtain a superior adhesive for dentures. The object of this invention is to provide an improved adhesive denture composition having strong adhesive properties and good resistance to washout, in order to provide long-lasting properties. These and other objects of the invention will be apparent to those skilled in the art from the following detailed description.

SUMMARY OF THE INVENTION The invention relates to a composition P1051-97 MX improved adhesive for dentures comprising a denture adhesive and a vehicle therefor. More particularly, the improved composition employs a denture adhesive which is a salt of a maleic anhydride copolymer and an alkyl vinyl ether having a specific viscosity of at least about 4. Improvement in one method is also part of this invention. to adhere a denture to the oral mucosa, resulting in the use of the new composition.

DESCRIPTION OF THE INVENTION The denture adhesive composition of the present invention contains an effective amount, for adhesion of a denture, of a denture adhesive and a pharmacologically acceptable carrier therefor. The denture adhesive typically comprises from about 15% to about 55% by weight of a denture adhesive composition. Preferably, it is between about 17% and 48% by weight and more preferably is about 30% in a cream formula and about 50% in a powder formula. The denture adhesive used in the composition is a salt of a maleic acid or maleic anhydride copolymer and P1051-97 MX an alkyl vinyl ether wherein the alkyl group has about 1 to 5 carbon atoms. The preferred copolymer is a copolymer of maleic anhydride and methyl vinyl ether. The polymer can be produced by any of the methods that are described in the technical literature or can be purchased commercially. However, according to the present invention, the copolymer has a molecular weight, which is represented by the specific viscosity measured as a 1% w / v solution of methyl ethyl ketone at 25 ° C, of at least about 4. Preferably, the specific viscosity is at least about 4.5. The copolymer is used in the form of a metal salt. Salts wherein only a portion of the acid groups have been reacted, for example, which are partially neutralized, are preferred. Preferred alkali cations include sodium, zinc, potassium, calcium and magnesium. Preferably the salts are mixed calcium / sodium or calcium / potassium salts, and more preferably are zinc / magnesium partial salts and sodium / zinc / magnesium salts. Examples of these magnesium salts are found in Patent Application No. (P / 1-929) filed on the same date as this application. That application is entitled "Adhesive for Dentures" and mentions Clarke, Ahn, Wong, Gas an, Smetana and Synodis P1051-97 MX as inventors. The statement of that application is mentioned here as a reference. Even when the salts of that request are preferred, this invention is not limited to the salts set forth in that application. When the salt is prepared, the metal compounds used react with the carboxylic acid groups in the copolymer and neutralize it. Preferably, less than 100% of the carboxylic acid groups in the copolymer chain are neutralized. More preferably, the metal compounds neutralize from about 50% to 90% of the carboxylic acid groups of the copolymer and more preferably from about 65% to 75% of the carboxylic acid groups. One of the particular advantages of this invention is that the use of the copolymer having a specific viscosity of at least about 4 allows a lower degree of neutralization to be employed in order to achieve a given level of adhesive performance for the denture. This means that the minimum cohesive force, necessary for a good adhesive performance for the denture, can be achieved by neutralizing less than the acid groups when the molecular weight of the copolymer is such that the specific viscosity of the copolymer is high. The use of a lesser degree of P1051-97 MX neutralization has its own advantages. As a result of the lower concentration of the metal cation, the fully hydrated polymer salt is a softer adhesive (it has a lower vitreous transition temperature) and moreover, it has a higher concentration of unreacted carboxyl groups. Polymers containing free and non-neutralized carboxyl groups are expected to have better adhesion, through hydrogen bonds with the functional carbonyl groups present in the acrylic plastic of the denture and with the oral mucosa, than the carboxylate anions present in a alkaline adhesive containing more metal cations. In addition, the higher molecular weight and the reduced degree of neutralization also reduce the tendency of the washout of the adhesive between the denture and the oral mucosa. The copolymer salt of this invention is made by dissolving the copolymer in a suitable solvent such as water. A high temperature can be used to make the dissolution of the polymer in the solvent faster, as long as the temperature is not so high as to have a detrimental effect on the polymer. Separately, a dispersion of the metal compound in water is prepared. Preferably, the solution of the metal compound also includes a catalyst, for example a base or Lewis acid, to facilitate the partial reaction of the compound P1051-97 MX metallic with carboxyl hydrogen in the polymer. By selecting the alkaline inorganic metal compound which is used to neutralize the carboxylic acid groups, the anionic portion of the compound is not restricted, although it is preferably an oxide, hydroxide, carbonate or halide. Of the halides, chloride is most preferred. In general, oxides and hydroxides are preferred due to their easy handling, availability and in general harmless nature of the by-products formed in their reaction with carboxylic acids. After the polymer solution has cooled sufficiently (when heated), the solution or dispersion of the metal compound and the polymer solution are combined and allowed to react. The product salt formed is dried, preferably milled to a size less than about 100 mesh and then dispersed in a pharmacologically acceptable carrier, to form the denture adhesive of this invention, using techniques known in the art. In addition to the denture adhesive, the composition contains a pharmacologically acceptable carrier. The pharmacologically acceptable carrier contains conventional materials and, if desired, may contain some adhesive adjuvant of those that have hitherto been used. For example, the vehicle may contain P1051-97 MX a carboxymethyl cellulose gum that is used to sensitize the adhesive to moisture and improve the cohesive properties of the formulation and improve gel strength. The carboxymethyl cellulose and carboxypropyl cellulose materials can also be used. When present, the cellulose gum preferably comprises from about 10% to about 30% by weight of the denture adhesive composition, more preferably from about 15% to about 25% and more preferably from about 20% by weight. about 22% of the composition for a cream formula. In a powder formula, the cellulose gum preferably comprises from about 45% to about 55% of the composition. The cellulose can be present in the form of a partial or complete salt, preferably a sodium salt. Non-active ingredients that may be present in the vehicle portion of the denture adhesive composition include: thickening agents, such as petrolatum, waxes, mineral oil and other oils; flavors, such as synthetic flavor oils and / or oils derived from plants and fruits, - colors suitable for food, drugs and cosmetic use and known as the FD &C; conservatives, like P1051-97 MX parabens, benzoic acid and similar benzoates; viscosity modifiers; and non-toxic agents against clod formation, such as silica, magnesium stearate and talc. In a cream formulation, the mineral oil or the like preferably comprises from about 10% to about 35%, more preferably from about 12% to about 17% by weight of the composition; the petrolatum and the like preferably comprises from about 20% to about 50%, more preferably from about 25% to about 45% by weight of the composition. In order to further illustrate the present invention, several examples are described below. In these, as in the entire specification and claims, all parts and percentages are by weight and the temperature is in degrees centigrade, unless otherwise indicated.

Example 1 A series of partially neutralized mixed salts of methyl vinyl ether / maleic anhydride copolymer are prepared in the following manner. 3.25 kilograms of distilled water are heated in a stirred reaction vessel at approximately 90 ° C; 253 grams of copolymer of P1051-97 MX methyl vyl ether / maleic anhydride is added slowly and mixed continuously until a clear solution is obtained. The solution is cooled to 65-75 ° C. Separately, 84 grams of calcium hydroxide and 13 grams of sodium hydroxide are dispersed in 500 grams of water. When the temperature of the copolymer solution has reached 65 to 75 ° C, the dispersion is added while mixing at high speed to avoid a localized reaction. The mixing continues for 15 minutes after the addition of the metal-containing dispersion is complete and the reaction mixture is then transferred to a series of shallow, steel drying trays which are placed in a convection oven. warm air at approximately 75 ° C for 18 to 20 hours. The dried partial salt is milled and passed through a 100 mesh screen.

Example 2 3.25 kilograms of distilled water are heated in a stirred reaction vessel at about 90 ° C. 257 grams of methyl vinyl ether / maleic anhydride copolymer are added slowly and mixed continuously until a clear solution is obtained. The solution is cooled to 65-75 ° C. Separately, a dispersion of P1051-97 MX 79.4 grams of calcium hydroxide and 13.2 grams of sodium hydroxide in 500 grams of water. When the temperature of the copolymer solution reaches 65-75 ° C, the dispersion is added while mixing at high speed to avoid a localized reaction. The mixing continues for 15 minutes, after the addition of the metal-containing dispersion ends, and the reaction mixture is transferred to a series of shallow, steel drying trays, which are placed in a convection oven. warm air at approximately 75 ° C for 18 to 20 hours. The dried partial salt is milled and passed through a 100 mesh screen.

Example 3_ 3.25 kilograms of distilled water are heated in a stirred reaction vessel at about 90 ° C. 262 grams of methyl vyl ether / maleic anhydride copolymer are added slowly and the mixture is continued until a clear solution is obtained. The solution is cooled to 65-75 ° C. Separately, a dispersion of 74.6 grams of calcium hydroxide and 13.4 grams of sodium hydroxide in 500 grams of water is prepared. When the temperature of the copolymer solution has reached 65-75 ° C, the dispersion is added while mixing at high speed to avoid a localized reaction. Continuous mixing P1051-97 MX 15 minutes after the addition of the metal-containing dispersion is complete and the reaction mixture is then transferred to a series of shallow steel drying trays which are placed in a convection oven of warm air at approximately 75 ° C for 18 to 20 hours. The dried partial salt is milled and sieved through a 100 mesh mesh.

Example 4 3.25 kilograms of distilled water, in a stirred reaction vessel, is heated to about 90 ° C. 266.7 grams of methyl vinyl ether / maleic anhydride are slowly added and continuously mixed until a clear solution is obtained. The solution is cooled to 65-75 ° C. Separately, a dispersion of 69.6 grams of calcium hydroxide and 13.7 grams of sodium hydroxide in 500 grams of water is prepared. When the temperature of the copolymer solution has reached 65-75 ° C, the dispersion is added while mixing at high speed to avoid a localized reaction. The mixture is continued for 15 minutes after the addition of the metal-containing dispersion has been completed and the reaction mixture is transferred to a series of shallow steel drying trays which are placed in an oven.

P1051-97 MX hot air convection at approximately 75 ° C for 18 to 20 hours. The dried partial salt is then milled and passed through a sieve through a 100 mesh.

Metallic Compound% Neutralized Example 1 Sodium hydroxide / calcium hydroxide 45 2 Sodium hydroxide / calcium hydroxide 30 3 Sodium hydroxide / calcium hydroxide 60 4 Sodium hydroxide / calcium hydroxide 80 Examples 5-8 A series of denture adhesive creams are prepared using the salts of Example 1. The respective salts are mixed with the other ingredients in the following manner. Mineral oil (approximately 17 parts) is heated to a temperature of approximately 75 ° C. Petrolatum (approximately 28 parts) is heated at the same temperature and added to the mineral and mixing oil until a uniform consistency is achieved. Sodium carboxymethyl cellulose (approximately 24 parts) the dye (0.05 parts), the antiterron agent, the preservative (0.05 parte) and the flavor (0.4 parts) are added while the mixture cools slowly to about 50 ° C. The salt partially mixed with P1051-97 MX copolymer is then added, at about 50 ° C, and the resulting denture adhesive cream is cooled to room temperature.

Examples 9-11 the shear strength of the adhesive was measured using three samples, homogeneously mixed, of the adhesive formulations of examples 5 to 8 and water in weight ratio of 1: 1, 1: 0.75 and 1: 0.5. Each combination was spread over about an area of 2.54 square cm of a transparent acrylic plate and then placed on the first plate, a second plate having a hole of 1.9 cm in diameter at one end. The resulting sandwich was held under a pressure of 20 pounds (9 kg) for 5 seconds and then set aside for about 5 minutes to allow hydration to occur. It was applied again pressure (approximately 20 pounds - 9 kilograms) for 5 seconds and then the shear strength was measured using an Instron Model 1122 machine. The result of the measurements was averaged. It was observed that a mixed sodium / calcium salt of methyl vinyl ether / maleic anhydride copolymer (specific viscosity of 4.7) had a better resistance to shear stress than a mixed partial salt of the 75% sodium / calcium copolymer with a P1051-97 MX specific viscosity of either 3.5 or 2.6.

Examples 12-15 Denture adhesive paste formulations containing a partial salt of a methyl vinyl ether / maleic acid / calcium anhydride 75% copolymer, using the following ingredients: sodium carboxymethyl cellulose (approximately 24 parts), petrolatum (approximately 28 parts), mineral oil (approximately 17 parts), colorant (approximately 0.05 parts) and preservatives (approximately 0.05 parts). Pastes in which the copolymer (before salt formation) had a specific viscosity of either 2.6, 3.5 or 4.7 were evaluated by a panel of denture wearers. Pastes in which the copolymers had a specific viscosity of 2.6 or 3.5 were perceived as equivalent whereas pastes in which the specific viscosity was 4.7 were found to exhibit a more durable and durable fixation.

Examples 16-18 Denture powders for dental dentures were prepared using partial sodium / calcium salts produced in Example 4. The respective salts were P1051-97 MX mixed dry with an equal weight of sodium carboxymethyl cellulose. The powders were evaluated by a panel of denture wearers. No statistically significant difference was observed in this test between the partial salts when the methyl vinyl ether / maleic anhydride copolymer had a specific viscosity of either 2.6 or 3.5. However, when the partial salt of the copolymer had been made from copolymer with a specific viscosity of 4.7, a statistically significant improvement in the development of the adhesive was observed. The high molecular weight salt had a more durable and stronger fixation than the lower molecular weight products. The various embodiments described in this application were established for purposes of further illustrating the invention and not intending to limit it. Changes and modifications to the modalities may be made without departing from the spirit and scope of the invention.

P1051-97 MX

Claims (27)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following CLAIMS is claimed as property: 1. A denture adhesive composition comprising a pharmacologically acceptable carrier and an effective amount for the adhesion of a salt of a maleic acid or maleic anhydride copolymer and an alkyl vinyl ether of 1 to 5 carbon atoms, wherein the copolymer has a specific viscosity of at least about 4.0.
2. 2. The denture adhesive according to claim 1, wherein the specific viscosity is at least about 4.5.
3. 3. The denture adhesive composition according to claim 2, wherein the carboxylic acid groups of the copolymer are not completely neutralized.
4. 4. The denture adhesive according to claim 3, wherein the alkyl entity is methyl. The denture adhesive according to claim 4, wherein the salt cation comprises a metal selected from groups IA, HA and IIIB of the Periodic Table.
5. P1051-97 MX
6. 6. The denture adhesive according to claim 4, wherein the salt cation is selected from the group consisting of sodium, potassium, calcium, zinc, magnesium, or mixtures thereof.
7. 7. The denture adhesive according to claim 6, in the form of a cream.
8. 8. The denture adhesive according to claim 7, wherein the denture adhesive is a mixed salt of the maleic anhydride copolymer and sodium / calcium methyl vinyl ether and the amount thereof is between about 15% and 55%.
9. 9. The denture adhesive according to claim 6, in the form of a powder.
10. The denture adhesive according to claim 9, wherein the denture adhesive is a mixed salt of the maleic anhydride copolymer and methyl vinyl ether and the amount thereof is between about 15% and 55%.
11. 11. The denture adhesive according to claim 1, wherein the carboxylic acid groups of the copolymer are not completely neutralized.
12. 12. The denture adhesive according to claim 1, wherein the alkyl entity is methyl.
13. 13. The denture adhesive according to claim 1, wherein the cation comprises a metal
14. P1051-97 MX alkaline. The denture adhesive according to claim 1, wherein the salt cation is selected from the group consisting of sodium, potassium, calcium, zinc, magnesium or mixtures thereof.
15. 15. The denture adhesive according to claim 1, wherein the amount of denture adhesive is between about 17% and 48%.
16. 16. The denture adhesive according to claim 1, in the form of a cream.
17. 17. The denture adhesive according to claim 16, wherein the amount of denture adhesive is about 30%.
18. 18. The denture adhesive according to claim 1, in the form of a powder.
19. 19. The denture adhesive according to claim 18, wherein the amount of denture adhesive is about 50%.
20. 20. The denture adhesive according to claim 1, which contains from about 10% to about 30% of a carboxymethyl cellulose gum.
21. 21. The denture adhesive according to claim 20, wherein the gum is sodium carboxymethyl cellulose, the amount thereof being about 15 to 53%. P1051-97 MX
22. 22. A method for adhering a denture to the oral mucosa using a denture adhesive composition using the denture adhesive composition of claim 1.
23. 23. A method for adhering a denture to the oral mucosa using a denture composition. denture adhesive that uses the denture adhesive composition The method of adhering a denture to the oral mucosa employing a denture adhesive composition utilizing the denture adhesive composition of claim 3. 25. A method for adhering a denture. to the oral mucosa employing a denture adhesive composition using the denture adhesive composition of claim 8. 26. A method for adhering a denture to the oral mucosa using a denture adhesive composition utilizing the denture adhesive composition of claim 10. 27. A method for adhering a denture to the oral mucosa using a denture adhesive composition using the denture adhesive composition of claim 20.

    P1051-97 MX