multivalent metal chloride a basic drug having an amino group and an ester group containing base material are dissolved or dispersed in a solvent and the obtained dissolved solution or a dispersed solution can be spread over a backing followed by removal of the solvent to form a drug layer thereby obtaining a patch if the blended ingredients can be applied by a hot melt process the ingredients are dissolved at a high temperature and the obtained solution can be spread over a backing to form a drug layer thereby obtaining a patch on a surface of the drug layer opposite to the backing a release liner may be further laminated in the above production processes the dissolved solution or dispersed solution may be spread over a release liner instead of a backing for forming a drug layer followed by laminating a backing together to obtain a patch examples of a solvent to be used for production according to a solvent process include a lower alcohol such as methanol ethanol and isopropanol toluene ethyl acetate hexane and cyclohexane as a backing layer a stretchable or non stretchable backing may be used for example it may be selected out of a cloth a nonwoven polyurethane polyester polyvinyl acetate polyvinylidene chloride polyethylene polyethylene terephthalate an aluminium sheet or a compound material thereof as a release liner specifically a film.