Bilastina: desenvolvimento de método analítico indicativo de estabilidade por clae/fluorescência e identificação de produtos de degradação por msms

Abstract

A method of liquid chromatography stability indicator (LC) was developed and validated for the quantitative determination of bilastine in coated tablets. The procedure was validated by specificity, linearity, robustness, precision and accuracy. The experimental design was used during the validation to determine the robustness of the method. Chromatographic separation was performed on a Shim-pack® RP-18 column (150 x 4.6 mm, 5 μm, Shimadzu, Kyoto, Japan) and fluorescence detection. The mobile phase comprises a mixture of 0.3% triethylamine (pH adjusted to 6.0 with 20% formic acid) and acetonitrile (52:48, v/v) at a flow rate of 1.0 mL/min with isocratic elution. Solutions were exposed to direct UV-C radiation, alkaline and acidic hydrolysis, thermal stress and an oxidation (hydrogen peroxide and metals) to evaluate the stability and peak-purity of bilastine. The method presented good recovery and precision (intra- and inter-day), and the response was linear in a range of 0.20 to 0.70 μg mL-1. The results demonstrated the robustness of the analytical method. The degradation products, formed under oxidative conditions with hydrogen peroxide, were isolated and the chemical structure of these compounds elucidated by high-resolution mass spectrometry.