Development and validation of a stability-indicating analytical method for simultaneous determination of drugs employed in canine leishmaniasis treatment

Abstract

We developed and validated a stability-indicating method for the simultaneous determination of allopurinol and ketoconazole in the pharmaceutical form of capsules. A Dionex® liquid chromatograph equipped with a diode array detector (DAD) and InertSustain® C18 column (4.6 x 100 mm x 3 μm) was used and InertSustain® C18 column (4.6 x 100 mm x 3 μm). The chromatographic separation occurred in the isocratic mode with a flow rate of 0.45 mL min-1 and mobile phase composed of acetonitrile: water (52:48 v/v) with pH adjusted to 3.0. The wavelengths used were 250 nm for allopurinol and 225 nm for ketoconazole. The method was validated by evaluating the parameters of linearity, limits of detection and quantification, precision, accuracy, robustness, and selectivity. The method presented linearity. It was precise, with coefficients of variation lower than 2.0%, and accurate, with recovery close to 100.00%. Robustness was indicated by the Plackett-Burman model, and the method was not significantly influenced by any of the variations. The selectivity was proven by the peak purities close to 1000 in both the presence of excipients and drug degradation products. Therefore the proposed method is simple and fast, with separation for both drugs less than four minutes.