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

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.