Direct quantification of anorethidrani disuccinate and determination of sterol metabolites by chemical derivatization combined with LC-MS/MS: Application to a Phase I pharmacokinetic study in humans.

Anorethidrani disuccinate (ACP) is a domestically designed A-decarbonized steroid that is currently being investigated in Phase I clinical trials for the treatment of solid tumors. Only the parent drug exhibited antitumor activity; its sterol metabolite M2 showed obvious antiestrogenic effects. We have developed a rapid, sensitive, and robust liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the direct quantification of ACP and a chemical derivatization method that can be used to quantify M2 derivatized with glycidyl trimethyl ammonium chloride (GTMA). A simple protein precipitation procedure was performed to quantify ACP. Injections were obtained within 3.5 min on an Eclipse Plus Phenyl-Hexyl column (50 mm × 2.1 mm i.d., 1.8 µm) with gradient elution; the calibration curve was linear over the range of 2.00-8000 ng/mL. For quantification of M2 in plasma, analytes were extracted by protein precipitation and converted to their GTMA derivatives at 60 °C for 2 h at pH 12; the analytes and coelutants were separated on a Luna C8(2) column (50 mm × 2.0 mm i.d., 5.0 µm). The precision (RSD) and accuracy (RE) of the intra- and interday determinations were within 10%. The derivatization procedure is a novel method for sterol determination by LC-MS/MS. The results confirmed the usefulness of this method for characterizing the pharmacokinetic profiles of ACP and its major metabolite M2 in a Phase I pharmacokinetic study.

Pharmacokinetics and pharmacodynamics of anordrin (2 alpha, 17 alpha-diethynyl-A-nor-5 alpha-androstane-2 beta, 17 beta-diol diproprionate).

In order to determine the pharmacokinetics of anordrin a dose of 0.2 mg/kg of [3-14 C]anordrin was administered i.v. to 5 cynomolgus monkeys; the same monkeys received the same dose i.m. at a later date. An additional 3 monkeys received 1.0 mg/kg of [3-14C]anordrin i.m. After administration of the compound, the dipropionate esters of anordrin were rapidly hydrolyzed to the dihydroxy parent compound, anordiol. After i.v. administration, anordrin had a mean residence time (MRT) of 5.0 +/- 1.3 (SE) min. [14C]Anordiol formed from [14C]anordrin had an MRT of 139 +/- 27 (SE) min. The metabolic clearance rates (MCR) of anordrin and anordiol were 55 and 34 mL/min.kg, respectively. The apparent volume of distribution at steady state (Vss) for anordrin was 276 mL/kg, 7.5% of body weight of the animals; anordrol had a much larger Vss of 4460 mL/kg. The MRT of anordiol after i.m. administration of 1.0 mg/kg of [14C]anordrin was 26.3 days. An average of 44% of the dose appeared in urine regardless of the route of administration or dose. The MRT values of total radioactivity were the same when calculated from serum or urine after an i.v. dose, but after i.m. administration, values from urine were approximately 60% of that calculated from serum, indicating that products appearing in urine had a shorter MRT than products appearing primarily in feces. A separate group of monkeys was given anordrin i.m. in doses ranging from 0.1 to 0.4 mg/kg on the first day of menses. The regression of length of menstrual cycle on dose was significant (P = 0.004).(ABSTRACT TRUNCATED AT 250 WORDS)