COMPARATIVE SERUM ESTRADIOL PROFILES FROM A NEW ONCE-A-WEEK TRANSDERMAL ESTRADIOL PATCH AND A TWICE-A-WEEK TRANSDERMAL ESTRADIOL PATCH

Two identical open-label, randomized crossover studies were conducted to compare serum estradiol profiles from the new 12.5- and 25-cm(2) on ce-a-week adhesive patches with those from the 10- and 20-cm(2) commer cially available twice-a-week Estraderm patches when applied as direct ed during a 1-week patch-wear period. Both studies were conducted in h ealthy postmenopausal women; serum estradiol levels were determined by gas chromatography/mass spectroscopy (GC/MS). Although both sizes of both patch treatments produced mean serum estradiol levels in the ther apeutic range, the once-a-week patch provided more constant mean level s, avoiding large peak-to-trough fluctuations. As expected, the differ ences in mean serum estradiol concentrations between the two patch tre atments occurred during the second application of the twice-a-week pat ch. Based on these results, the once-a-week drug in adhesive patch app ears to be an acceptable means of hormone replacement therapy.