STABILITY STUDY OF PRAVASTATIN UNDER HYDROLYTIC CONDITIONS ASSESSED BY HPLC

Abstract

In this work all HPLC stability-indicating method was developed and applied to study the hydrolytic behavior of pravastatin in different pi-Is and temperatures. From the system suitability test, the selected chromatographic conditions were a C-18 column, acetonitrile-30 mmol L-1 phosphate buffer solution pH 2 (28:72) as mobile phase, 40 degrees C temperature column, a flux of 1 mL/min and 239 nm as wavelength detection. The developed method exhibited an adequate repeatability and reproducibility (CV 0.11% and 0.49%, respectively) and a recovery higher than 98%. Furthermore, the detection and quantitation limits were 3.4x10(-7) mol L-1 and 3.7x10(-6) mol L-1. The kinetic degradation of pravastatin fits to a pseudo-first order kinetic. The degradation was pH-dependent: alkaline pH < acid pH and the generation of degradation products was dependent of the media tested (one product in alkaline medium and 4 products in acid medium). Activation energy, kinetic rate constants at different temperatures, t(1/2) and t(90) values are also reported.