High-performance liquid chromatography with diode array detection method for the simultaneous determination of seven selected phosphodiesterase-5 inhibitors and serotonin reuptake inhibitors used as male sexual enhancers

This work presents a simple, sensitive and generic high-performance liquid chromatography with diode array detection method for the simultaneous determination of seven drugs prescribed for the treatment of erectile dysfunction and premature ejaculation.

Investigated drugs include the phosphodiesterase-5 inhibitors: sildenafil, tadalafil and vardenafil, in addition to the selective serotonin reuptake inhibitors: dapoxetine, duloxetine, fluoxetine and paroxetine. The drugs were separated using Waters C8 column (4.6×250 mm, 5 μm) with the mobile phase consisting of phosphate buffer pH 3, acetonitrile and methanol in the ratio 60:33:7. The flow rate was 1.2 mL/min, and quantification was based on measuring peak areas at 225 nm. Peaks were perfectly resolved with retention times 3.3, 3.9, 6.4, 7.5, 9.5, 10.7 and 13.4 min for vardenafil, sildenafil, paroxetine, duloxetine, dapoxetine, fluoxetine and tadalafil respectively. The developed method was validated with respect to system suitability, linearity, ranges, accuracy, precision, robustness and limits of detection and quantification. The proposed method showed good linearity in the ranges 5-500, 2-200, 2-200, 3-300, 1.5-150, 2-200 and 2-200 μg/mL for sildenafil, tadalafil, vardenafil, dapoxetine, duloxetine fluoxetine and paroxetine, respectively. The limits of detection were 0.18-0.38 μg/mL for the analyzed compounds. The applicability of the proposed method to real life situations was assessed through the analysis of commercial tablets, and satisfactory results were obtained. This article is protected by copyright. All rights reserved.

Journal of separation science. 2016 Mar 11 [Epub ahead of print]

Mostafa M Baker, Tarek S Belal, Mohamed S Mahrous, Hytham M Ahmed, Hoda G Daabees

Methodology Department, Pharco Pharmaceuticals Company, Alexandria, Egypt., Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, University of Alexandria, Alexandria, Egypt., Pharmaceutical Chemistry Department, Faculty of Pharmacy, University of Alexandria, Alexandria, Egypt., Pharmaceutical Analysis Department, Faculty of Pharmacy, Damanhour University, Damanhour, Egypt., Pharmaceutical Chemistry Department, Faculty of Pharmacy, Damanhour University, Damanhour, Egypt.