Liquid Chromatographic Procedure for the Quantitative Analysis of Megestrol Acetate in Human Plasma

Abstract

A simple, sensitive, and reproducible high-performance liquid chromatographic (HPLC) procedure was developed for the quantitative analysis of mégestrol acetate in human plasma. An internal standard, 2,3-diphenyl-indenone, was added to 0.5mL of plasma followed by extraction with hexane. The residue remaining after evaporation of hexane was reconstituted in methanol and injected onto a μ-Bondapak C18 column. The column was eluted with acetonitrile:methanol: water:acetic acid (41:23:36:1), and the eluant was monitored at 280nm. Megestrol acetate and the internal standard eluted at 6–7 and 12–14 min, respectively. The peak height ratio (megestrol acetate/internal standard) versus plasma concentration was linear over a range of 10–600ng of megestrol acetate/mL of plasma, and the limit of detection was 5ng/mL. The mean intra- and interassay accuracies were within 3% of the actual values. The mean intra- and interassay precision, as estimated by RSD, were 4 and 6%, respectively. Constituents in human plasma and megestrol, a possible degradation product, did not interfere in the assay. The procedure was applied to the analysis of plasma samples from subjects receiving 40mg of Megace q.i.d.