Stability Indicating High Performance Liquid Chromatographic Assay for the Determination of Sildenafil Citrate in Bulk and in Formulations

Differential Pulse Voltammetric Determination of Sildenafil Citrate (Viagra®) in Pharmaceutical Formulations Using a Boron-Doped Diamond Electrode

“…Optimization of the experimental parameters yielded a detection limit of 6.4 Â 10 À7 mol L À1 for sildenafil, which is quite similar to the lowest one obtained by voltammetric methods by Ö zkan et al (2004) using a polished glassy carbon electrode and higher than those obtained by Berzas et al (2000) using a HMDE. On the other hand, addition and recovery tests were satisfactory, with values similar to those obtained using a comparative HPLC method (Abd-Elbary et al 2004). Finally, it should be noted that the proposed method is fast and simple to carry out; thus, it is a promising alternative for the quantitative determination of sildenafil, following only the dissolution of the sample, dispensing any use of organic reagents or expensive apparatus.…”

“…The results showed good recoveries for the commercial tablets, ranging from 91.5% to 101%, indicating that there is not any important matrix interference for the samples analyzed by the proposed DPV method. Table 1 presents the sildenafil amounts determined in commercial tablets of different dosages employing the proposed DPV method and a comparative HPLC method (Abd-Elbary et al 2004). Three determinations were carried out for each sample, and the standard deviations were calculated.…”

“…At the moment, there is no official method in any pharmacopoeia (e.g., USP, BP, or EP) related to the determination of sildenafil in tablet dosage forms or in bulk. Nevertheless, several analytical methods were developed for the determination of sildenafil in pharmaceutical formulations, using colorimetry (Amin, Moustafa, and El-Dosoky 2009), spectrophotometry (Altiokka et al 2001;Dinesh et al 2002;Sagar 2004;Rao et al 2006;Harikrishna, Nagaralli, and Seetharamappa 2008;Los Weinert, Pezza, and Pezza 2008), nearinfrared spectroscopy (NIRS) (Vredenbregt et al 2006), Raman spectroscopy (de Veiji et al 2008), and chromatography (Abd-Elbary, Foda, and El-Gazayerly 2004;Abourashed, Abdel-Kader, and Habib 2005;Daraghmeh et al 2001;Ergun et al 2005). However, most of these methods present characteristics that affect their usefulness for routine analysis, such as need of expensive instrumentation, careful control of reaction conditions or derivatization reactions, and tedious sample preparation.…”

Letter to the Editor

“…HPLC methods for detecting sildenafil, in both pure and pharmaceutical form, are well established in recent literature (see, for example, [1][2][3][4][5]). It has been shown that excipients, such as citrate, lactose, etc., do not interfere with detection and measurement.…”

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

“…Daraghmeh et al [7] reported an HPLC technique for the determination of sildenafil citrate and its related substances. Recently, Abd-Elbary et al [8] proposed an HPLC procedure for the determination of sildenafil citrate in bulk and in formulations. Structure elucidation of sildenafil analogues in herbal products was made by Blok-Tip et al [9].…”