ORAL PHARMACOKINETIC STUDY OF EXEMESTANE SMEDDS AND SUSPENSION IN RAT PLASMA BY LIQUID CHROMATOGRAPHY-MASS SPECTROMETRIC ANALYSIS

To evaluate the bioavailability of exemestane (EXM) from self-micro emulsifying drug delivery systems (SMEDDS) and suspension formulations, a sensitive, specific, and rapid liquid chromatography-mass spectrometric method was developed and validated. The analyte was extracted from plasma samples and detected by mass spectrometry (MS) with an atmospheric pressure positive-ion chemical ionization (APCI) mode using a heated nebulizer interface. Progesterone (PGS) was used as the internal standard. A Hychrome RPB-L428 column was used to perform the chromatographic separation, the mobile phase being methanol and 15 mM ammonium formate (80:20). The MS detection used a heated nebulizer interface, with multiple reaction monitoring (MRM) operated in positive-ion mode. Both, EXM and PGS were well-separated and identified by their relative retention times, that is, 1.13 and 1.84 min, respectively. After oral administration of EXM loaded SMEDDS and suspension formulation to rats, a significant difference was observed ...