Title:  Betamethasone- and hyaluronic acid-treated thin adhesive plaster for the treatment of psoriasis dermatitis and dermatosis

United States Patent:  6,379,695

Assignee:  Altergon S.A. (Lugano, CH)

Filed:  October 22, 1999

Foreign Application Priority Data:  Mar 05, 1999[IT] (MI99A0449)

Thin adhesive plaster having a thickness lower than 500 .mu.m for the treatment of psoriasis, dermatitis and dermatosis, comprising: a) a support comprising an outer layer in plastic film and an inner layer in woven or non-woven fabric having approximately the same size as the plastic film, b) an adhesive layer placed on the support inner layer having approximately the same size as the support comprising an adhesive matrix in the form of hydrogel, betamethasone or a pharmaceutically acceptable salt thereof and optionally hyaluronic acid or a pharmaceutically acceptable salt thereof, c) a protective plastic film contacted with the adhesive layer and removable immediately prior to use.

DETAILED DESCRIPTION OF THE INVENTION

The adhesive plaster according to the present invention preferably contains both active ingredients in the adhesive layer.

Betamethasone is present in the adhesive plaster according to the present invention as betamethasone valerate; the hyaluronic acid preferably has a molecular weight ranging from 30,000 to 1,200,000, and more preferably from 30,000 to 300,000, and is preferably present as sodium salt. The adhesive plaster being the object of the present invention is generally 200 to 500 .mu.m thick and preferably 250 to 480 .mu.m thick.

The support outer layer is a film made of a polymeric material preferably selected from a group comprising polyethylene, ethylene-methyl methacrylate copolymer, polypropylene; the support inner layer is made of woven or non-woven fabric, preferably selected from the group comprising polyethylene, polypropylene, rayon. Adhesive layer (b) contains an adhesive hydrogel matrix comprising polyacrylic acid in an aqueous dispersion, with a polyacrylic acid concentration ranging from 0.1 to 9% by weight in respect of the adhesive layer total weight.

According to a preferred embodiment, the aqueous dispersion used is as found in commerce under the trademark AC10H.RTM.; its viscosity ranges from 10,000 to 50,000 mPa.s. and its polyacrylic acid content is in a concentration of 20% by weight.

The aforesaid aqueous dispersion is added in concentrations ranging from 10 to 30% by weight, and preferably in a concentration of 20% by weight, in respect of the adhesive layer total weight.

The adhesive plaster adhesive layer preferably weighs 150 to 400 m² /g and is 120 to 280 .mu.m thick.

According to a preferred embodiment, the adhesive layer contains betamethasone valerate in a concentration of 0.05 to 5% by weight, and more preferably of 0.1% by weight in respect of the adhesive layer total weight, and sodium hyaluronate in a concentration of 0.1% to 3% by weight and still more preferably of 0.2% by weight in respect of the adhesive layer total weight.

The adhesive layer may contain excipients selected from preservatives, wetting agents, thickeners, cross-linking agents, pH adjusters, stabilisers, etc., and mixtures thereof.

The thickeners preferably used are sodium polyacrylate having a molecular weight of 450,000 to 4,000,000, polyacrylic acid having a molecular weight of 450,000 to 4,000,000, sodium carboxymethylcellulose or mixtures of said thickeners. The preservatives preferably used are methylparaben, propylparaben, and more preferably mixtures of the said preservatives. The cross-linking agent is preferably dihydroxyaluminium amino acetate. The wetting agent is preferably selected from the group comprising glycerol, butylene glycol, propylene glycol or mixtures thereof. The stabiliser is preferably sodium edetate; the pH adjuster is preferably tartaric acid.

The adhesive plaster according to the present invention is prepared on the basis of the following method. The hydrocolloidal matrix is co-extruded between the support film and the protective plastic film to be removed immediately prior to use. The preparation of the adhesive plaster according to the invention is reported in the following examples, conveyed by way of indication.

Claim 1 of 11 Claims

What is claimed is:

1. An adhesive plaster having a thickness lower than 500 .mu.m consisting of:

a) a support consisting of an outer layer in plastic film and an inner layer in woven or non-woven fabric having approximately the same size as the plastic film,

(b) an adhesive layer placed on the support inner layer approximately the same size as the support, said layer consisting essentially of an adhesive matrix in the form of hydrogel, betamethasone valerate, sodium hyaluronate, a thickener, a preservative, a wetting agent, a cross-linking agent, a stabilizer and a pH adjuster, and

(c) a protective plastic film contacted with the adhesive layer and removable immediately prior to use wherein the concentration of betamethasone valerate in the adhesive layer is 0.1% by weight and the concentration of sodium hyaluronate in the adhesive layer is 0.2% by weight.

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