Determinação de lamivudina em matéria prima e solução oral por espectrometria UV com formação do complexo azul de timol e cromatografia líquida de alta eficiência

Abstract

Ultraviolet spectrophotometric with tymol blue complex (Method I) and high performance liquid chromatographic (Method II) methods were developed. The validated methods were applied for quantitative determination of lamivudine in raw material and oral solution. UV spectrophotometric determinations were made using thymol blue complex at 270 nm, with ethanol solution 9:1. Liquid chromatographic analysis was carried out on a LiChrospher ®100 RP18 (250x4.6 mm, 0.5μ) column. Methanol:water (50:50 v/v) was used as mobile phase at a flow rate of 1.0 mL/min with UV detection at 270 nm. The retention time of lamivudine was 2.7 min. Analytical curves were linear within a concentration range from 8.0 at 16.0 g/mL for Method I and to 20.0 at 100.0 g/mL, for method II, with correlation coefficients of 0.9999 and 0.9985, respectively. The relative standard deviation (RSD) was 0.38% for raw material and 0.89% for oral solution, using method I. The corresponding values were 0.42% % and 0.90% using method II. The percentage recoveries were around 100% for both methods. The results showed that method II was the most appropriated for lamivudine determination in oral solution, because the excipent can be interfere in the results of method I.