Pharmacokinetic behavior of 16-dehydropregnenolone after intramuscular administration in rats

The pharmacokinetics of 16-dehydropregnenolone (16-DHP), a sterols compound isolated from Solanum lyratum Thunb., was investigated in rats following a Single intramuscular administration (40 mg/kg). The concentration of 16-DHP in rat plasma was determined by a high Performance liquid chromatography (HPLC) method with UV detection. Levonorgestrel was used as the internal Standard (IS). The pharmacokinetic parameters of 16-DHP were derived by non-compartmental method. After a Single intramuscular administration, the maximum plasma concentration (Cmax) was (289 ± 25) ng/mL, time to reach Cmax(tmax) was (0.38 ± 0.14) h, the elimination half-life (t1/2) was (2.5 ± 1.1) h, the area under the plasma concentration-time curve from time zero to the time of the last measurable concentration (AUC(0-t)) was (544 ± 73)ng · h/mL. The results indicated that 16-DHP was absorbed quickly and eliminated rapidly in rats after the intramuscular injection.