Pharmacokinetics of estradiol, progesterone, testosterone and dehydroepiandrosterone after transbuccal administration to postmenopausal women

OBJECTIVE: To evaluate the pharmacokinetic profiles of estradiol, progesterone, testosterone and dehydroepiandrosterone in postmenopausal women following single and multiple dosing using a troche and the transbuccal route of administration. METHODS: Each troche contained estradiol (0.5 mg), progesterone (200 mg), testosterone (2.0 mg) and dehydroepiandrosterone (10 mg). A half troche was administered to each of six women and the plasma concentration-time profiles determined over 24 h. Thereafter, a one-half troche was taken twice daily for 2 weeks and concentrations determined over a dosage interval (12 h). Blood and saliva samples were collected at specified time intervals on the first day and again after 2 weeks. RESULTS: Each of the hormones was readily absorbed via the buccal mucous membrane. Peak plasma concentrations of estradiol and progesterone were comparable to those found normally in young menstruating women. CONCLUSION: The transbuccal route is a novel approach to provide therapy for the management of menopause-related symptoms of postmenopausal women without the need to resort to conjugated or synthesized hormones, and may overcome the poor or erratic systemic availability associated with other routes of administration.