Pharmacokinetics and adhesion of a transdermal patch containing ethinyl estradiol and gestodene under conditions of heat, humidity, and exercise: A single-center, open-label, randomized, crossover study.

In this open-label, randomized study, 36 women (18-45 years) applied an ethinyl estradiol/gestodene contraceptive patch once-weekly for 3 weeks followed by a 1-week, patch-free interval, in 3 treatment periods. The primary objective was to evaluate the pharmacokinetics of ethinyl estradiol and gestodene under conditions of heat, humidity, and exercise. The secondary objective was to evaluate patch adhesion under the same conditions. Weeks 1 and 2 of each period comprised "standardized normal activity" (SNA); in week 3, SNA continued or women used a sauna, whirlpool, swimming pool, or performed an exercise combination. Thirty-one women completed the study; 23 yielded evaluable pharmacokinetic data. Analyses were exploratory and conducted using an analysis of variance. Area under the concentration-time curve from 0 to 168 hours (AUC0-168 ) for gestodene and ethinyl estradiol during sauna, swimming, and whirlpool was equivalent to previous SNA recordings. For exercise combination, the gestodene AUC0-168 was 12% lower compared with SNA, albeit not considered clinically relevant. Two women lost a total of 3 patches during sporting activities; other detachments during this week were not correlated with sporting activity. Overall, hormone delivery using the ethinyl estradiol/gestodene patch under conditions of heat, humidity, and exercise corresponded to delivery under normal conditions.