DEVELOPMENT OF A NEW NICOTINE TRANSDERMAL DELIVERY SYSTEM - IN-VITRO KINETICS STUDIES AND CLINICAL PHARMACOKINETIC EVALUATIONS IN 2 ETHNIC-GROUPS

Nicotine transdermal delivery systems (nicotine-TDSs) have provided ef fective assistance to smokers in smoking cessation with minimal occurr ence of withdrawal symptoms. However, substantial skin reactions have been reported with the four nicotine-TDSs marketed recently. To reduce the skin reactions, a new type of nicotine-TDS has been recently deve loped. In vitro skin permeation studies demonstrated that this nicotin e-TDS yields a constant skin permeation profile with a permeation rate of 0.068 (+/-0.003) mg/cm2/h across human cadaver skin and 0.059 (+/- 0.014) mg/cm2/h across hairless rat skin, which are comparable to the steady-state permeation rates attained by Habitrol(TM) and Nicoderm(R) systems. The clinical pharmacokinetic evaluations in two ethnic group s of smokers indicated that a steady-state nicotine plasma level has b een maintained throughout the course of 24-h topical application. Whil e a higher daily dosage of nicotine has been delivered transdermally t o Taiwanese smokers, from all three patch sizes, than to American smok ers, no clear demographic effect was detected in most pharmacokinetic parameters between these ethnic groups, even after taking the differen ce in subjects body weight into consideration.