Uv stable transdermal plaster

Abstract

The invention relates to a UV stable transdermal therapeutic system (TTS) consisting of a back layer, at least one matrix containing an active substance and optionally, a withdrawal film and an UV-radiation absorber. An adhesive layer containing said UV-radiation absorber is arranged between the back layer and the matrix containing an active substance which is distant as much as possible from a surface, a separation layer is arranged between the adhesive layer containing said UV-radiation absorber and the matrix containing an active substance, which is as remote as possible from the surface which is impermeable to the active substance and UV-radiation absorber. The inventive transdermal therapeutic system exhibits a high stability and is devoid of inconveniences of existing TTS containing a light-sensitive substance.

1 . Transdermal therapeutic system (TTS) consisting of a backing layer, of at least one active ingredient-containing matrix and optionally of a detachable sheet, and comprising a UV absorber, characterized in that
 at least one UV absorber-containing adhesive layer is provided between the backing layer and the active ingredient-containing matrix which is furthest away from the surface of the skin,   at least one separating layer which is impermeable to active ingredient and impermeable to the UV absorber is present between the adhesive layer containing the UV absorber and the active ingredient-containing matrix which is furthest away from the surface of the skin.   
     
     
         2 . Transdermal therapeutic system according to  claim 1 , characterized in that the sequence of layers in the system starting from the side facing away from the skin is backing layer, UV absorber-containing adhesive layer, separating layer and finally a mono- or bilayer active ingredient-containing matrix whose pressure-sensitive adhesive surface is covered by a detachable protective sheet. 
     
     
         3 . Transdermal therapeutic system according to  claim 1 , characterized in that the weight per unit area of the adhesive layer is from 5 to 50 g/m 2 , preferably 20 to 30 g/m 2 . 
     
     
         4 . Transdermal therapeutic system according to  claim 1 , characterized in that the separating layer has a layer thickness of from 4 to 23 μm, preferably from 4 to 10 μm. 
     
     
         5 . Transdermal therapeutic according to  claim 1 , characterized in that the separating layer consists of a barrier polymer, preferably of polyethylene terephthalate, polyacrylonitrile, polyvinyl chloride, polyvinylidene chloride or its copolymers or colaminates. 
     
     
         6 . Transdermal therapeutic according to  claim 1 , characterized in that the matrix and/or the adhesive layer is/are designed to be self-adhesive and consists/consist essentially of polymers selected from the groups of polyisobutylene, polybutene, polyacrylate, polydimethylsiloxane, styrene/isoprene block polymer or polyisoprene. 
     
     
         7 . Transdermal therapeutic system according  claim 1 , characterized in that the weight per unit area of the matrix is from 30 to 150 g/m 2 , preferably 50 to 120 g/m 2 . 
     
     
         8 . Transdermal therapeutic system according to  claim 1 , characterized in that the backing layer is permeable to active ingredient and preferably consists of polypropylene, polyethylene, polyurethane, ethylene/vinyl acetate copolymer or a multilayer composite of these materials with one another or with other materials. 
     
     
         9 . Transdermal therapeutic system according to  claim 1 , characterized in that the UV absorber is present in dissolved form in the adhesive layer in a concentration of from 0.5 to 10% (m/m), preferably 1.0 to 5.0% (m/m). 
     
     
         10 . Transdermal therapeutic system according  claim 1 , characterized in that exclusively the adhesive layer has/have the UV absorber(s). 
     
     
         11 . Transdermal therapeutic system according to  claim 1 , characterized in that the UV absorber is/are selected about a substance or a mixture of substances from the group of p-aminobenzoic acid, aminobenzoic acid derivative, preferably 2-ethylhexyl 4-dimethylaminobenzoate and/or polyethoxyethyl 4-bis(polyethoxyl)aminobenzoate, cinnamic acid, cinnamic acid derivatives, preferably isoamyl 4-methoxycinnamate and/or 2-ethylhexyl 4-methoxycinnamate, 3-benzylidenebornan-2-one, benzylidenebornan-2-one derivatives, preferably 3-(4′)-methylbenzylindenebornan-2-one, 3-(4-sulphone)benzylindenebornan-2-one and/or 3-(4′-trimethylammonium)benzylidenebornan-2-one methylsulphate, salicylic acid derivative, preferably 4-isopropylbenzyl salicylate, 2-ethylhexyl salicylate, and/or 3,3,5-trimethylcyclohexyl salicylate, benzotriazoles, preferably 2-(5-chloro-2H-benzotriazole-2-yl)-6-(1,1-dimethylethyl)-4-methylphenol, 2,4,6′-trianiline-p-(carbo-2′-ethylhexyl-1′-oxy)-1,3,5-triazine, 3-imidazol-4-ylacrylic acid, 3-imidazol-4-yl-3-imidazol-4-ylacrylic ester, 2-phenylenebenzimidazole-5-sulphonic acid and/or its K, Na and triethanolamine (=TEA) salts, 2-cyano-3,3-diphenylacrylic acid, terephthaloylidenedicamphorsulphonic acid, butylmethoxydibenzoylmethane, benzophenone and/or benzophenone derivatives, preferably benzophenone-3 and/or benzophenone-4. 
     
     
         12 . Transdermal therapeutic system according to  claim 1 , characterized in that the UV absorber(s) is/are colourless or yellowish. 
     
     
         13 . Transdermal therapeutic system according to  claim 1 , characterized in that the system is transparent or slightly opaque. 
     
     
         14 . Transdermal therapeutic system according to  claim 1 , characterized in that at least one hormone acts as active ingredient. 
     
     
         15 . Transdermal therapeutic system according to  claim 1 , characterized in that the active pharmaceutical ingredient(s) is/are progestogen(s), preferably gestodene or levonorgestrel. 
     
     
         16 . Transdermal therapeutic system according to  claim 1 , characterized in that the transdermal therapeutic system has no membrane controlling the release of active ingredient.