LC-MS/MS quantification of progesterone in ovariectomized miniature swine and its application for preliminary pharmacokinetic study of a novel vaginal sustained release system

Abstract

Objective We here established a simple, fast, robust and sensitive LC-MS/MS method and validated as well for the quantitative analysis of progesterone (PGT) in ovariectomized (OVX) miniature swine plasma. The method was successfully applied to characterize the pharmacokinetics of a progesterone vaginal drug delivery system. Methods Megestrol acetate was utilized as an internal standard (IS). The separation and detection of PGT from endogenous interference was performed successfully by liquid chromatography with gradient elution and mass spectrometry equipped with positive ESI source using MRM mode. The EVA intravaginal rings (IVRs) were manufactured by hot-melt extrusion (HME), afterward were administrated vaginally to OVX minipigs to evaluate PK study. Results The calibration curve for swine plasma samples across the concentration ranged between 0.25 ng/mL and 100 ng/mL. The intra- and inter-assay accuracy and precision were lower than ±5% and 5.88%, respectively. Recoveries of PGT and IS were ranging from 114–119% and 96.5–112%, respectively. In vitro study showed that the EVA IVRs release 18 mg/day of PGT continuously over 7 days, and corresponding mean PGT plasma concentration in OVX minipigs (CAVG) was 4.892 ng/mL. Conclusion All the study produced reliable results for the measurement of PGT concentration in miniature swine plasma and the method was successfully applied to a PK study for PGT vaginal ring in miniature pigs, which may lay the foundation for further research on the progesterone preparations intended for in assisted reproductive technology.