A patch which is provided with a patch member and a cover member, wherein: the patch member is provided with a support layer and a drug reservoir layer which is laminated on one surface of the support layer and which contains both a drug and a drug reservoir base the cover member is provided with a cover layer and a pressure -sensitive adhesive layer which is laminated on one surface of the cover layer and which contains a pressure-sensitive adhesive base the patch member and the cover member are arranged in such a way that the pressure-sensitive adhesive layer is laminated on the other surface of the support layer and the solubility parameter (SPa)of the drug, the solubility parameter (SPb) of the drug reservoir base and the solubility parameter (SPc) of the pressure-sensitive adhesive base satisfy all of the relationships (1) to (3): 0 &le SPa-SPb &le 1.5 ... (1) 2.0 &le (SPa-SPc) &le 2.8 ... (2) 1.0 &le (SPb-SPc) &le 2.8... (3).本發明係一種附覆蓋材料之貼附劑,其係具備貼附劑及覆蓋材料者,並且上述貼附劑具備支持體層、及積層於上述支持體層之一面上且含有藥物及藥物貯存基劑之藥物貯存層,上述覆蓋材料具備覆蓋層、及積層於上述覆蓋層之一面上且含有黏著基劑之黏著層,上述貼附劑及上述覆蓋材料係以於上述支持體層之另一面上積層上述黏著層之方式配置,上述藥物之溶解度參數(SPa)、上述藥物貯存基劑之溶解度參數(SPb)、及上述黏著基劑之溶解度參數(SPc)同時滿足下述式(1)~(3)所表示之條件:0≦SPa-SPb≦1.5 (1)2.0≦(SPa-SPc)≦2.8 (2)1.0≦(SPb-SPc)≦2.8 (3)。1‧‧‧附覆蓋材料之貼附劑10‧‧‧貼附劑20‧‧‧覆蓋材料101‧‧‧支持體層102‧‧‧藥物貯存層201‧‧‧覆蓋層202‧‧‧黏著層
