title: Single dose pharmacokinetics of gestodene in women after intravenous and oral administration.
abstract: Six healthy female volunteers (age 25 - 39 years) received 75 micrograms gestodene intravenously followed by 3 oral administrations of 25, 75 and 125 micrograms gestodene together with 30 micrograms ethinylestradiol (EE2) in a cross-over design. Gestodene plasma levels were determined using a specific RIA. After intravenous administration, plasma gestodene concentrations decayed triphasically with mean half-lives of 0.16 h, 1.5 h and 10 hours. The area under the plasma level curve, the total plasma clearance and the volume of distribution (VZ) were as follows: AUC = 35 +/- 15 ng.h/ml, CL = 0.80 +/- 0.53 ml/min/kg, and VZ = 0.66 +/- 0.43 1/kg, respectively. After oral administration of all doses, maximum plasma levels of 1.0 (25 micrograms), 3.8 (75 micrograms) and 7.0 ng/ml (125 micrograms) were achieved between 1.4 and 1.9 hours after the intake. Post-maximum levels showed 2 disposition phases with half-lives of 1 and 12 - 14 hours. Absolute bioavailabilities were calculated as 87.5 +/- 17.5% (25 micrograms), 99.3 +/- 10.9% (75 micrograms) and 110.8 +/- 17.7% (125 micrograms) indicating that gestodene is completely absorbed and systemically available at all doses investigated.
authors.affiliation: Research Laboratories, Schering AG, Berlin, West Germany.
authors.forename: U
authors.initials: U
authors.lastname: Täuber
authors.forename: J W
authors.initials: JW
authors.lastname: Tack
authors.forename: H
authors.initials: H
authors.lastname: Matthes
mesh_terms: D000284:Administration, Oral; D000328:Adult; D001682:Biological Availability; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D009652:Norpregnenes / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism
chemical_list: D009652:Norpregnenes; D012738:Sex Hormone-Binding Globulin; C033273:Gestodene