Avaliação da presença de aminas estimulantes, diureticas e anorexigenas em suplementos alimentares empregando eletroforese capilar

Abstract

The consumption of dietary supplements has been increasing in recent years, due to its easy acquisition in both physical stores and websites. It is demonstrated mainly by the billionaire income of the global market involving dietary supplements. Thus, new products are launched frequently and increasingly appealing as to their rapid effectiveness related to fat burning and weight loss. It leads to an alarming scenario in relation to the safety of these products, since fraud and adulteration in the formulations are quite recurrent. In this context, the National Health Surveillance Agency (Anvisa) published a few years ago the regulatory framework for dietary supplements in order to standardize, regularize and narrow the gaps in the legalization of these products. Thus, it is necessary to have fast, sensitive and selective analytical methods for investigating the most probable mixtures of drugs as potential adulterants. This work proposed the development of an analytical method employing capillary electrophoresis with UV and C4D detection based on the micellar electrokinetic chromatography (MEKC) technique for the study and determination of 10 drugs (caffeine, synephrine, yohimbine, fenproporex, amfepramone topiramate, sibutramine, hydrochlorothiazide, furosemide and amiloride). From selectivity criteria, the method was validated for 5 drugs studied in the initial hypothetical mixture (caffeine, synephrine, yohimbine, hydrochlorothiazide and femproporex). The method was applied in the study of 20 samples of dietary supplements marketed in Brazil using the following optimized analytical conditions: working electrolyte phosphate buffer 50 mmol L-1 (pH 9.6) containing 20% acetonitrile (v/v) and sodium dodecyl sulfate (SDS) 50 mmol L-1, separation potential -15 kV, temperature 25 °C, hydrodynamic injection by gravity at 20 cm for 50 s. The method was validated according to the parameters of linearity, limit of detection, limit of quantification, precision and accuracy. In the studied samples, it was possible to detect that 20% of the samples contained hydrochlorothiazide as a diuretic drug and 5% had a caffeine concentration above that considered acceptable doses. Of the 5 drugs validated in the method by MEKC, caffeine, synephrine, hydrochlorothiazide and yohimbine were detected and quantified in the studied samples. The method proved to be effective in identifying stimulants, diuretics and anorectic as adulterants present in dietary supplements with good selectivity and detection sensitivity.