Solid phase extraction and liquid chromatographic determination of sildenafil and N-demethylsidenafil in rat serum with basic mobile phase

Simultaneous determination of sildenafil and N-desmethyl sildenafil in human plasma by high-performance liquid chromatography method using electrochemical detection with application to a pharmacokinetic study

“…Liquid chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry (LC/MS/MS) are expensive and thus unavailable in many laboratories. High-performance liquid chromatographic methods with UV detection have been reported for the simultaneous determination of sildenafil and its active metabolite [9][10][11][12][13]. Among others, these methods involved automated sequential 0731 trace enrichment of dialysate (ASTED), dual and triple column switching, as well as semi microbore, microbore and nanobore HPLC methods to enhance sensitivity and reduce retention time [11].…”

Quantitative analysis of sildenafil and desmethylsildenafil in human serum by liquid chromatography–mass spectrometry with minimal sample pretreatment

“…This requires additional investments. Guermouche and Bensalah [6] used a off-line SPE procedure. It is our experience SPE requires 2-3 times more pretreatment time then the protein precipitation procedure.…”

“…Sildenafil is excreted predominantly as metabolites in faeces (80%) and to a lesser extent in urine (13%). Several methods have been described to quantify sildenafil and its metabolite in plasma samples, using liquid chromatography and mass spectrometry [4][5][6][7][8][9]. These methods include a pretreatment of the samples with liquid-liquid extraction (automated) solid phase extraction or automated sequential trace enrichment.…”

Liquid chromatography tandem mass spectrometry assay to determine the pharmacokinetics of aildenafil in human plasma

“…So far, various methods have been developed for the quantification of the sildenafil and vardenafil in biological samples, such as micellar electrokinetic capillary chromatography (MEKC) [2,3], gas chromatography-mass spectrometry (GC/MS) [4], electrochemical detection [5,6] and high-performance liquid chromatography (HPLC) with ultraviolet [7][8][9][10][11], Diode array [12], MS [13][14][15], and MS/MS [16][17][18] detection. However, to our knowledge, no reference to any assay method for aildenafil quantification could be found in literature.…”

“…However, to our knowledge, no reference to any assay method for aildenafil quantification could be found in literature. Moreover, the aforementioned methods [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] suffer from various limitations, such as low sensitivity, relatively complex sample preparation, and long analytical run time. Based on the sensitivity, selectivity, and high-throughput of LC-MS/MS methods, we report here the first quantitative method to determine aildenafil in human plasma with LC-MS/MS using sildenafil as the internal standard (I.S.).…”