Abstract
Transdermal delivery systems containing nitroglycerin, isosorbide dinitrate and estradiol have already been in the Japanese market, and those of eperizone hydrochloride and tulobuterol are coming. Separately, topical formulations like NSAID plasters are also in the market. Through the R&D on such formulations, criteria of designing the systems and selecting the pharmaceutical additives and materials have been established, resulting in development of potential skin-penetration enhancers and iontophoresis. In addition, non-needle syringes and skin-adhesive injections are producing, which may be similar to transdermal drug delivery systems. Thus, skin will be a potential site of drug administration of many kinds of drugs to improve quality of life especially for aged patients, together with the GI tract, an absorption site of oral formulations.
