Desenvolvimento e validação de metodologia para avaliação de rimonabanto e estudo da sua dissolução a partir de formas farmacêuticas

Abstract

Rimonabant is a selective antagonist of the cannabinoid type 1 (CB1) receptor indicated as an adjunct to diet and exercise for the treatment of obese patients (BMI ≥ 30 kg/m2), or overweight patients (BMI > 27 kg/m2) with associated risk factors, such as type 2 diabetes or dyslipidaemia. In the present study, a reversed phase liquid chromatographic method was developed and validated for quantitative analysis of rimonabant in pharmaceutical products, and also a dissolution testing has been developed for coated tablets and capsules. The chromatographic method for determination of rimonabant in pharmaceutical formulations was performed on a Gemini C18 (150 × 4.6 mm i.d., 5 μm) column, with a mobile phase composed of acetonitrile: water (75:25, v/v), which was pumped at a flow-rate of 1 mL min-1 and ultraviolet detection at 215 nm. The analytical assay was validated by evaluating the parameters specificity, linearity, precision, accuracy, robustness, limit of detection and quantification, giving results within the acceptable range as defined by international validation guidelines. The selected conditions for the dissolution testing were 900 mL of 0.15% sodium lauryl sulfate in water as dissolution medium, USP apparatus 2 (paddle), stirring speed of 50 rpm and drug analysis by liquid chromatography. A study was assessed to compare some commercially available drug products, such as film-coated tablets (brand name Acomplia®) and compounded capsules from different suppliers. The physicalchemical tests applied to samples were average weight, content uniformity, active substance assay and dissolution profile, which have showed distinct results. In addition, rimonabant capsules containing different excipients were prepared for evaluation of formulation parameters on in vitro release profile of the drug.