title: Stable-isotope methodology in the bioavailability study of 17 alpha-methyltestosterone using gas chromatography-mass spectrometry.
abstract: The application of a stable-isotope coadministration technique for estimating the relative bioavailability of 17 alpha-methyltestosterone is described. Eight healthy male subjects were administered orally a single 10-mg 17 alpha-methyltestosterone tablet together with a 10-mg 17 alpha-methyltestosterone-d3 solution. The serum concentrations of 17 alpha-methyltestosterone and 17 alpha-methyltestosterone-d3 were determined by gas chromatography-mass spectrometry with selected ion monitoring using 17 alpha-methyltestosterone-d6 as an internal standard. The extent of absorption from the tablet formulation was comparable to that from the oral solution. The stable-isotope methodology was compared with the conventional cross-over method for evaluating the bioavailability of 17 alpha-methyltestosterone.
mesh_terms: D000042:Absorption; D000328:Adult; D001682:Biological Availability; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007700:Kinetics; D008297:Male; D008777:Methyltestosterone / Q000097:blood / Q000378:metabolism*
chemical_list: D008777:Methyltestosterone