Validation of sibutramine and phenolphthalein determination by HPLC-PDA innatural dietary supplements for body-weight reduction

The worldwide demand for natural dietary supplements for body-weight reduction is increasing, because they are commonly believed to be safe. However, the abundance and diversity of available dietary supplements impede their quality control, potentially posing multiple health risks. A simple and cost-effective procedure involving high-performance liquid chromatography photodiode array detector (HPLC-PDA) and homogeneous liquid– liquid extraction (LLE) of samples were applied to analyze simultaneously sibutramine and phenolphthalein in natural dietary supplements used for body-weight reduction. The recoveries obtained ranged from 91.87% to 96.46%. The limits of detection and quantification were 0.33 μg/mL and 1 μg/mL, respectively. The phenolphthalein and sibutramine contents were in the range of 0.009-5.601 mg/tablet and 0.005-4.409 mg/ tablet, respectively. The results showed that the proposed HPLC-PDA method was precise and accurate. It was simple to apply to identify and quantify these and other adulterants in natural dietary supplements.