The present invention relates to a denture adhesive composition.

Denture adhesive compositions are required to adhere a denture to the gum. Proper adhesion is required so that the denture can be sued effective without providing discomfort for the user by allowing slipping or by allowing food residue to penetrate beneath the denture.

There is a continued need for improved denture adhesive compositions. According to a first aspect of the invention there is provided a denture adhesive composition, comprising:

a) at least one component comprising a C5 to C15 polyalkene, and

b) a viscosity index improver.

Preferably the C5 to C15 polyalkene comprises a polyalphaolefin. For clarity the term C5 to C15 polyalkene refers to the chain length of the monomers which make up the polymeric polyalkene.

With the use of the at least one component comprising a C5 to C15 polyalkene it has been found that effective / advantageous adhesive compositions may be provided.

A principle advantage is that the composition provides a high level of "standing" viscosity and in particular that they can be easily discharged from the tubes in which the denture adhesive compositions are typically contained / sold. Thus preferably the compositions are shear- thinning.

Most preferably the denture adhesive composition is free of mineral oils and polymers of comprising C2-C4 species; especially C2 (polyethylene or polymers comprising ethylene). A secondary advantage associated with the compositions of the present invention is that the detrimental properties of these entities can be ameliorated or even avoided.

C5 to C15 polyalkene

Generally the at least one component comprising the C5 to C15 polyalkene is present in the composition in a total amount of from 20 to 60 wt% based on the total weight of the composition. Most preferably the total amount of C5 to C15 polyalkene present in the composition is in the range of from 30 to 50%wt and most especially 35-45%wt.

The at least one component comprising the C5 to C15 polyalkene may be a gel or an oil component. Most preferably the compositions comprise both a gel component comprising C5 to C15 polyalkene and an oil component comprising C5 to C15 polyalkene. It is preferred that the composition comprises C5 to C15 polyalkene in a gel component form. The amount of C5 to C15 polyalkene present in the composition in this gel component is preferably 10% to 35%wt, more preferably 15% to 30%wt, especially 20 to 25%wt based on the total weight of the composition. It is also preferred that the composition comprises C5 to C15 polyalkene in an oil form and the amount thereof is preferably 5% to 30%wt, more preferably 10% to 25%wt, especially 15 to 20%wt based on the total weight of the composition.

It is especially preferred that the compositions of the invention comprise C5 to C15 polyalkene in a gel component form and also C5 to C15 polyalkene in an oil form, with the preferred amounts of both forms being as given above.

It is preferred that the gel form comprises the C5 to C15 polyalkene together with the viscosity index improver as a pre-mixed ingredient. In this case it is preferred that the viscosity index improver comprises a hydrogenated styrene isoprene copolymer.

It is preferred that the oil form comprises only the C5 to C15 polyalkene.

Preferably the C5 to C15 polyalkene is in at least partially and most preferably fully hydrogenated form. Where both a gel and an oil form of the C5 to C15 polyalkene are present in the composition it is preferred that both are in at least partially and most preferably fully hydrogenated form.

Generally the C5 to C15 polyalkene has a molecular weight between 300 and 1500g/mol, and especially 400 and 1000 g/mol. Suitable alkenes for producing the polyalkene include pentene, hexene, heptene, octene, nonene, decene, undodecene and dodecene, preferably decene.

A particularly preferable polyalphaolefin is food grade polydecene, especially hydrogenated polydecene and most preferably fully hydrogenated polydecene.

Viscosity Index Improver

By the term "viscosity index improver" is meant a material which is capable of thickening a C5 to C15 polyalkene oil but which does not act as an adhesion promotor in the composition.

Generally the viscosity index improver is present in an amount from about 0.001% to about 20.0% by weight of the composition. Most preferably the viscosity index improver is present in an amount of 0.5% to 10%wt, such as 1% to 7 %wt and most preferably 2 to 5 %wt of the composition.

Preferably the viscosity index improver is selected from the group consisting of polymethacrylates, olefin copolymers, hydrogenated styrene-diene copolymers, styrene polyesters, rubber, polyvinylchloride, nylon, fluorocarbon, polyurethane prepolymer, polyethylene, polystyrene, polypropylene, acrylic resins, microcrystalline wax, elastomers, poly(alkyl fumarate co-vinyl acetate), alkylated polystyrene, poly(t-butyl styrene), and combinations thereof.

Most preferably the viscosity index improver comprises a hydrogenated styrene isoprene copolymer. Preferably in the gel component comprising C5 to C15 polyalkene and the viscosity index improver, the ratio of the C5 to C15 polyalkene and the viscosity index improver is in the range of from 20:1 to 5:1 by weight.

Denture adhesive component

The compositions of the invention optionally, but preferably comprise a denture adhesive component. The adhesion promotor aids the adhesion of the compositions to the gums and/or to the dentures.

Preferably the denture adhesive composition comprises a denture adhesive component selected from the group consisting of cellulose, cellulose derivatives including cellulosic resins, poly(n-butyl vinyl ether), poly(styrene-co-maleic anhydride), starch, starch derivatives, saccharide, saccharide derivatives, polyethylene oxides, polyethylene glycols, polyvinyl alcohols, carrageenan, alginates, karaya gum, xanthan gum, guar gum, gelatin, algin, tragacanth, chitosan, acrylamide polymers, carboxypolymethylene, polyamines, polyquaternary compounds, polyvinylpyrrolidone, polylvinylalkylacrylates /maleic anhydride copolymers and salts thereof including mixed salts, , polymeric acids, polymeric salts, polyhydroxy compounds, and combinations thereof.

An especially preferred adhesion promotor is a polyvinylmethacrylate/maleic anhydride copolymer, especially the mixed calcium/sodium salt thereof. Carboxymethylcellulose, salts of carboxymethylcellulose are also preferred adhesion promotors. A combination to polyvinylmethacrylate/maleic anhydride copolymer and a carboxymethylcellulose, especially sodium carboxymethylcellulose is especially preferred as an adhesion promotor.

Generally the denture adhesive component is present in an amount from 20 to about 75%, more preferably 30 to 70%wt, especially 40 to 65%wt based on the total weight of the composition.

The composition may contain other adjunct materials such as fillers, pH adjusting agents, preservatives, dyes / colourants, flavourings.

Preferably the denture adhesive composition can be dispensed from a tube by hand.

An especially preferred denture adhesive composition according to the present invention comprises;

a) a C5 to C15 polyalkene oil, and

b) a gel component comprising a C5 to C15 polyalkene oil and a viscosity index improver.

Preferably this composition comprises hydrogenated C5 to C15 polyalkene in both the oil and the gel, and most preferably fully hydrogenated C5 to C15 polyalkene. It is especially preferred that the gel component comprises hydrogenated styrene isoprene copolymer as the viscosity index improver. It is also preferred that this denture adhesive composition can be dispensed from a tube. Unless stated otherwise, all amounts herein are stated as percentages by weight based on the total weight of the composition.

According to a second aspect of the invention there is provided a method of using a denture adhesive composition comprising applying the composition to a denture, inserting the denture in the ora l cavity, bring the denture into contact with a gum and applying pressure to same.

According to a third aspect of the invention there is provided a method of preparing a denture adhesive composition wherein an oil component comprising a C5 to C15 polyalkene is formed into a base with the viscosity index improver before the remaining ingredients are added thereto.

In particular, an oil component comprising C5 to C15 polyalkene is optionally mixed with dyes and/or flavours. The adhesive promoter is added to this mixture (or oil if no dyes or flavours have been added. Next a gel component comprising C5 to C15 polyalkene and viscosity index improver is added and finally the cellulosic gums are added. At each stage the mixture is stirred until the ingredients are well mixed.

Preferred compositions according the invention are given in the tables below. Further examples within the scope of the invention will be appa rent to the person skilled in the art. All amounts are given as percentages by weight based on the total weight of the composition.

Table 1;

Table 2;