LC determination of finasteride and its application to storage stability studies

The development of a simple, sensitive, rapid, and reproducible reversed-phase high-performance liquid chromatographic assay of finasteride (proscar) in preformulation, and its application to forced degradation studies has been carried out. The method showed excellent linearity (r2 > or = 0.9997) in the range 20-600 microg x ml(-1) using a Shimpak C8 column (5 microm, 15.0 cm x 4.6 mm) and UV-detection (210 nm) at ambient temperature (25 +/-1 degree C) with a mobile phase of acetonitrile and water (95:05,v/v) and flow rate of 0.7 ml x min(-1). All peaks are eluted in < 10 min and the method has good precision. This method showed good efficiency for the analysis of forced degraded samples, studied at different temperatures and humidities. The results manifest that the shelf-life of proscar is greater than two years at room temperature, under proper storage conditions.