title: The in vivo release characteristics of a multi-compartment vaginal ring releasing 3-keto-desogestrel.
abstract: The results of a stage I study of a new vaginal ring releasing 3-keto-Desogestrel [3kDOG] is reported. The study design consisted of one study cycle, where the ring was used continuously for 21 days and then removed. Twenty healthy volunteers were randomly allocated to each of two study groups. On day 5 of the menstrual cycle, group A used a vaginal ring releasing 30 micrograms 3kDOG per 24 hours and group B used a 15 micrograms 3kDOG per 24 hours ring. After initial absorption of the 3kDOG a plateau phase was reached in 46 hours [group A] and 49 hours [group B]. On reaching the plateau phase, the overall decline in plasma levels during the 21 days of use was 5.24% for group A and 5.27% for group B. This represents a daily decline in plasma levels of 0.27% and 0.28% for the 30 micrograms and 15 micrograms per 24 hours rings, respectively. The plasma levels achieved by the rings were significantly different throughout (p = 0.011). On removal after 21 days, the mean removal half-life for both ring types was similar at 20.9 hours for group A and 21.1 hours for group B. It is concluded that the characteristics of the delivery system are worthy of further study as a potential means of contraception using 3kDOG delivered from a vaginal ring.
authors.affiliation: Department of Obstetrics and Gynaecology, University of Birmingham, U.K.
authors.forename: R
authors.initials: R
authors.lastname: Jackson
authors.forename: J R
authors.initials: JR
authors.lastname: Newton
mesh_terms: D000282:Administration, Intravaginal; D003274:Contraceptive Devices, Female; D017135:Desogestrel; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D009652:Norpregnenes / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D009652:Norpregnenes; C044815:etonogestrel; D017135:Desogestrel