A capillary zone electrophoretic method for the determination of hypoglycemics as adulterants in herbal formulations used for the treatment of diabetes

Abstract

Adulteration of antidiabetic herbal medicines with hypoglycemic drugs has been reported as a recurrent practice throughout the world. In this context, a new method for the determination of metformin, chlorpropamide, glibenclamide and gliclazide by capillary zone electrophoresis (CZE) with capacitively coupled contactless conductivity detection (C⁴D) is described in this paper. The proposed method was applied to the evaluation of adulterants in samples of herbal formulations commercialized by compounding pharmacies for the treatment of diabetes mellitus. The method was shown to be suitable for the simultaneous evaluation of hypoglycemics as adulterants using a 20 mmol L⁻¹ sodium acetate solution at pH 10.0 as the working electrolyte. The method allows for the quantification of the adulterants in concentrations higher than 0.24 mg per capsule for metformin, 0.42 mg per capsule for chlorpropamide, 0.15 mg per capsule for glibenclamide and 0.33 mg per capsule for gliclazide.