| abstract |
A transdermal therapeutic system in the form of a matrix or reservoir system, characterized by containing - At least one pharmaceutical active principle of basic or neutral reaction - An adhesive contact polymer, which has units of acrylic acid or methacrylic acid in a part of the polymer chain , the content of carboxyl groups being 0.5 to 10.0% (m / m) referred to the average polymeric mass and the carboxyl groups being in the form of alkaline or alkaline earth salts with a stoichiometry of 5-100%, preferably of 10-50% There may also be hygroscopic additives in the formulation to avoid moisture sensitivity. |