Development of a Liquid Chromatographic Method for the Determination of Sildenafil in Seminal Plasma.

A sensitive high performance liquid chromatographic(HPLC) method with ultraviolet absorption detection(230 nm) was developed and validated for the determination of a phosphodiesterase V inhibitor, Sildenafil, in seminal plasma. A single step liquid–liquid extraction procedure using ethyl acetate was performed to recover sildenafil from 1.0 mL of seminal plasma combined with 200 µL of NaOH 0.1 M. A symmetry C18 column(150 × 4.6 mm I.D. 5 µm) was used as a stationary phase and the mobile phase consisted of 32% acetonitrile and 68% phosphoric acid(0.016 M; pH 5.3) at a flow rate of 1.0 mL/min. The quantitation limit was 5 ng/mL. Intra- and inter-day relative standard deviation(RSD) did not exceed 6.6%. This HPLC method has been successfully used in medical laboratories to assay seminal plasma samples for studies on the treatment with sildenafil. [ABSTRACT FROM AUTHOR]