Abstract
Background: A variety of pharmacological effects have been attributed to ursolic acid, however, its hydrophobicity has made clinical application difficult. In this sense, the development of nanoparticles containing ursolic acid may represent an improvement in drug solubility.
Objective: In this study, a simple HPLC method with PDA detection was developed and validated for the quantitative determination of ursolic acid in poly(lactic acid) (PLA) nanoparticles.
Method: The method was validated as per ICH guidelines considering the parameters linearity, limits of detection and quantification, specificity, accuracy, precision and robustness. The mobile phase employed was a mixture of acetonitrile and water (90:10, v/v) under isocratic elution with a flow rate of 1 mL/min. Ursolic acid was detected at 203 nm.
Results: The method proved to be linear in the range of 10 – 100 µg/mL and the limits of detection and quantitation were 0.50 and 1.53 µg/mL, respectively. Precision (intra-day and inter-day) presented relative standard deviation below 2%. Accuracy was assessed by the recovery test of ursolic acid from nanoparticles. Robustness was demonstrated altering the mobile phase and flow rate. Specificity showed no interference from components of formulation or degradation products from light exposure.
Conclusion: The method was successfully employed to determine the content of ursolic acid in PLA nanoparticles.
Keywords: Ursolic acid, HPLC, nanoparticles, poly(lactic acid).