Development and validation of HPLC/DAD method for simultaneously determination of six prohibited substances in model matrices

Abstract

The authorities have identified an emerging trend where over-the-counter products, represented as dietary supplements, contain hidden active ingredients that could be harmful. Consumers may unknowingly take products laced with varying quantities of approved prescription drug ingredients, controlled substances, and untested and unstudied pharmaceutically active ingredients. Hidden ingredients are increasingly becoming a problem in products promoted for sexual enhancement, weight loss, or bodybuilding. The tests have revealed the presence of some undesired substances like sildenafil, tadalafil, vardenafil, and their analogues in tainted sexual enhancement products. The content of these substances is usually around the daily curative dose. A simple high-performance liquid chromatography (HPLC) method for simultaneously determination of sildenafil, vardenafil, tadalafil, dapoxetine, yohimbine, and sibutramine was developed and validated. InfinityLab Poroshell 120 EC-C18 (150 '4.6 mm '4 μm particles) was used, as well as a diode-array detector (DAD) at 230 nm, and a gradient flow with 0.030 М ammonium acetate buffer and acetonitrile. The method is linear in the following range: 2.5–37.5 μg/mL for yohimbine, 2.06–30.9 μg/mL for vardenafil, 2.0–30.0 μg/mL for sildenafil, 3.1–46.5 μg/mL for tadalafil, 1.98–29.7 μg/mL for dapoxetine, and 2.2–66.0 μg/mL for sibutramine. The linearity coefficient is R2 = 1 for all substances. Model matrices were spiked, and the analytical recoveries for all substances are in the range 97.5%–99.5%. The method exhibited an upper hand compared with previously reported methods in terms of speed and simplicity. Additionally, the mobile phase (also used as extracting, column washing, and diluting solvent) was composed of only buffer and acetonitrile, which rendered the method much cheaper than others.

Sildenafil 4.0—Integrated Synthetic Chemistry, Formulation and Analytical Strategies Effecting Immense Therapeutic and Societal Impact in the Fourth Industrial Era

“…Simple, fast and sensitive high-performance liquid chromatography (HPLC) methods have been developed and validated for the determination of sildenafil citrate in pharmaceutical preparations. The methods refer to reverse phase chromatography and their conditions are summarized in Table 4 [ 152 , 153 , 154 , 155 , 156 , 157 , 158 ]. The parameters evaluated were the detection wavelength, the type and amount of the organic modifier, the salt concentration and the pH of the mobile phase.…”

Development and Validation of Stability‐Indicating HPLC Method for Simultaneous Quantification of Vardenafil and Dapoxetine in Bulk and in Combined Dosage Form

“…Various analytical methods have been reported for their quantitative determination in bulk and/or dosage forms, either singly or in combination. [8][9][10][11] Vardenafil was determined using different analytical techniques such as HPLC, [12,13] mass spectroscopy (MS), [14][15][16] electrochemical, [17] and TLC, [18] while the methods used for the determination of dapoxetine were spectrophotometry, [8,19] and HPLC. [20,21] The procedures used for the simultaneous determination of both vardenafil and dapoxetine, such as fluorescence spectroscopy, [22] spectrophotometry, [8,23] HPLC, [23][24][25] and the TLC densitometric method, [26] A drug's safety is a major factor in its development, not only in terms of the intact drug itself but also in terms of its impurities and degradation products.…”

“…Vardenafil hydrochloride and dapoxetine hydrochloride are not listed in any pharmacopoeia. Various analytical methods have been reported for their quantitative determination in bulk and/or dosage forms, either singly or in combination [8–11] . Vardenafil was determined using different analytical techniques such as HPLC, [12,13] mass spectroscopy (MS), [14–16] electrochemical, [17] and TLC, [18] while the methods used for the determination of dapoxetine were spectrophotometry, [8,19] and HPLC [20,21] .…”

A Rapid Screening Method for Sibutramine Hydrochloride in Natural Herbal Medicines and Dietary Supplements

“…To date, numerous detection methods for sibutramine hydrochloride adulteration in NHM and DS for weight loss have been developed including thin-layer chromatography (TLC) [ 17 , 18 ], gas chromatography mass spectrometry (GC-MS) [ 19 , 20 ], liquid chromatography (LC) [ 21 , 22 ], liquid chromatography-mass spectrometry (LC-MS) [ 21 , 23 – 27 ], ion exchange chromatography (IEC) [ 28 ], capillary electrophoresis (CE) [ 29 ], capillary zone electrophoresis (CZE) [ 30 ], nuclear magnetic resonance (NMR) [ 31 ], ion mobility spectrometry (IMS) [ 32 ], infrared spectroscopy (IR) [ 33 ], micellar electrokinetic capillary chromatography (MECC) [ 34 ], X-ray powder diffraction (XRPD), and colorimetry [ 35 , 36 ]. However, there are several disadvantages of these methods including long assay time, expensive instrumentation, and the need for skilled operators.…”