FINASTERIDE IN BIOLOGICAL-FLUIDS - EXTRACTION AND SEPARATION BY A GRAPHITIZED CARBON-BLACK CARTRIDGE AND QUANTIFICATION BY HIGH-PERFORMANCELIQUID-CHROMATOGRAPHY

A simple, specific and sensitive high-performance liquid chromatograph ic method has been developed and validated for the determination of fi nasteride in human plasma. A solid-phase extraction procedure was used to isolate finasteride from the biological matrix before quantitative analysis. The analyte was separated on a Symmetry reversed-phase colu mn using acetonitrile-0.04 M orthophosphoric acid (pH 4.0) as mobile p hase and quantified by measuring its UV absorbance at 215 nm. The limi t of detection for the analyte was 0.005 mu g/ml. 4-Androstene-3,17-di one was used as internal standard. The calibration graph of the method was linear from 0.01 to 3.0 mu g/ml of finasteride in human plasma, a nd the coefficient of variation less than 4.5%. This HPLC procedure is simple, precise and accurate for the determination of finasteride in human plasma.