Validated spectrofluorimetric method for determination of two phosphodiesterase inhibitors tadalafil and vardenafil in pharmaceutical preparations and spiked human plasma

Abstract

A valid, sensitive and rapid spectrofluorimetric method has been developed and validated for determination of both tadalafil (TAD) and vardenafil (VAR) either in their pure form, in their tablet dosage forms or spiked in human plasma. This method is based on measurement of the native fluorescence of both drugs in acetonitrile at λem 330 and 470 nm after excitation at 280 and 275 nm for tadalafil and vardenafil, respectively. Linear relationships were obtained over the concentration range 4-40 and 10-250 ng/mL with a minimum detection of 1 and 3 ng/mL for tadalafil and vardenafil, respectively. Various experimental parameters affecting the fluorescence intensity were carefully studied and optimized. The developed method was applied successfully for the determination of tadalafil and vardenafil in bulk drugs and tablet dosage forms. Moreover, the high sensitivity of the proposed method permitted their determination in spiked human plasma. The developed method was validated in terms of specificity, linearity, lower limit of quantification (LOQ), lower limit of detection (LOD), precision and accuracy. The mean recoveries of the analytes in pharmaceutical preparations were in agreement with those obtained from the comparison methods, as revealed by statistical analysis of the obtained results using Student's t-test and the variance ratio F-test.

Stability assessment of tamsulosin and tadalafil co‐formulated in capsules by two validated chromatographic methods

“…On reviewing literature, TMS was quantified by several methods, namely; TLC [16][17][18], HPLC in different matrices [18][19][20][21], capillary electrophoresis [16], spectrophotometry [16,[22][23][24], and electrochemical methods [16,25]. For TAD, several methods were reported for its determination includ-ing TLC [26][27][28][29], HPLC [26,[30][31][32][33][34][35][36], gas chromatography [26,37], capillary electrophoresis [26], spectrophotometry [26,[38][39][40][41], and electrochemical methods [42][43][44].…”

Micellar Enhanced Synchronous Fluorescence for the Assay of Sumatriptan Succinate in Pharmaceutical Tablets

“…Spectrofluorimetic methods of analysis are considered as sensitive and simple for the determination of many pharmaceutical active species in different samples [25,26]. To our knowledge there is no analytical method based on native fluorescence of SUM, in this study, it was found that SUM exhibits an emission fluorescence spectrum at about 350 nm after excitation at 225 nm in aqueous medium ( fig.…”

Liquid Chromatography-Tandem Mass Spectrometry Method for the Determination of Vardenafil and Its Application of Bioequivalence

“…is method has a relatively long run time of 18 min and the LLOQ remained high (10 ng/mL) [11]. Abu El-Enin et al (2015) developed a spectrofluorimetric method to quantify vardenafil in human plasma and pharmaceutical products [12]. Despite the simple protein precipitation method with acetonitrile only, this method requires a large amount of human plasma (1 mL) to achieve an LLOQ of 10 ng/mL [12].…”