RESUMO
Drug absorption through the skin can vary according to the application site. The nicotine transdermal system, Nicoderm (Alza Corp., Palo Alto, CA) contains a rate-controlling membrane designed to regulate delivery of nicotine to the skin and thus limit variability in nicotine plasma levels. Plasma nicotine concentrations were compared after application of NTS 14 mg/day to three different skin sites (upper back, upper outer arm, upper chest) in a randomized, crossover study involving 12 healthy male smokers. Plasma nicotine profiles from all three sites were similar: nicotine concentrations increased rapidly within 2 to 4 hours, reached broad peaks of approximately 11 to 14 ng/mL, and then remained relatively constant between 8 and 24 hours after application. The mean nicotine maximum peak plasma concentration values for nicotine transdermal system application to the arm, back, and chest were equivalent (13.8, 14.6, and 13.2 ng/mL, respectively). The mean time to reach peak concentration (tmax) (3 to 6 hours), and area under the curve (168, 186, and 183 ng.h/mL) values for the arm, back, and chest, respectively, were not significantly different. Thus, bioequivalent plasma nicotine concentrations were achieved irrespective of the application site on the upper body.
