Semi-solid Dosage Forms and Transdermal Drug Delivery System

－Usefulness of Topical and Systemic Patches－

Abstract

Transdermal patches both of topical and systemic use is a useful and user friendly pharmaceutics. Poultice containing ketoprofen features the cross-linking network between aluminum and sodium polyacrylate and is a swollen hydrogel. Large amount of drug, water and other additives can be contained in the poultice. Ketoprofen is easily released from poultice and absorbed into the skin. In addition, microdialysis technique is used for evaluation of percutaneous penetration of ketprofen in pigs. These results show the topical patches containing ketprofen can deliver the drug through the skin and knee joint via direct diffusion. It was found that poultice containing ketoprofen is a useful and user friendly formulation for patients. Adhesives are one of important excipients for development of systemic transdermal patches. Newly developed acrylic adhesive (AAEM-ad) could contain lots of liquid substance with sufficient cohesion and had the properties of high release rate and skin permeation. The bioequivalence is shown between original product and AAEM-ad patch containing tulobuterol. New adhesion tests are listed in Japanese pharmacopoeia 17th edition such as peel test, ball tac test, rolling ball tac test and probe tac test, the same as drug release test for seeking a high evidence of patches.