Bioequivalency of Samagra tablet formulations of SDI in healthy volunteers using HPLC.

Abstract

Abstract A simple and reliable assay method in clinical laboratory was designed for determination of sildenafil citrate, in a plasma samples by using Solid_ Phase extraction (SPE, C-18) method and high_ performance liquid chromatography. Solid Phase extraction (SPE) was an efficient sample for extraction with a recovery of about 91%, sildenafil have found to have linear dynamic range of 5.0 _ 1000 ng /ml. Twenty healthy male volunteers with average age of 32±12 years old received 25 mg of each of the two sildenafil formulations; (SDI, Samagra) and Kamagra (India), there was a one week wash out period between doses. The plasma were purified on SPE mini column, then the drugs molecules were separated on reversed phase ( 250 X 4.6 mm i.d) C-18 column , using Acetonitrle : 50 µM formic acid buffer pH (4.5). ( 15 : 85 v/v) . The eluted drug were monitor on UV set at 230 nm. With a detection limit of 5.0 ng / ml. Plasma concentration-time curve were monitored by HPLC over a period of 18 hours after administration of both drugs. Maximum plasma sildenafil concentration Cmax for Samagra was ( 150±7.15 ng/ml) and Cmax for(Kamagra) India (160.5 ± 6.80 ng / ml ) respectively both reach maximum concentrations of sildenafil at about 1 hour obtained from plasma concentration _ time curve data.The results indicate no significant difference between the two formulations, therefore both medication of sildenafil are bioequivalent.