Simultaneous analysis of highly polar pharmaceutical adulterants in slimming products by hydrophilic interaction liquid chromatography

ABSTRACTA chromatographic method utilizing hydrophilic interaction liquid chromatography was developed for the estimation of highly polar pharmaceutical adulterants in commercial slimming products. Five adulterants, phenylpropanolamine, salbutamol, phenformin, buformin, and metformin, were successfully separated on an XBridge™ amide column (3.5 µm, 4.6 × 250 mm) using a mobile phase composed of acetonitrile/26.5 mM ammonium formate containing 0.1% formic acid (85:15) flowing at the rate of 0.8 mL/min. Wavelengths for monitoring the elution of these compounds were determined based on the wavelength of their absorption maxima (λmax = 208, 226, and 236 nm). The developed method was validated for specificity, linearity, accuracy, precision, and robustness. Interassay comparison showed that the performance of the hydrophilic interaction liquid chromatography-based method was superior to that of the traditional reversed-phase liquid chromatography-based method. Therefore, the proposed method is useful to analyz...