Determination of ursolic acid from polymeric nanoparticles using high-performance liquid chromatography method

The objective of this work was to determine a reversed-phase (RP) high-performance liquid chromatography (HPLC) method for the in vitro pharmaceutical characterization of ursolic acid-loaded polymeric nanoparticles. Chromatographic runs were performed on a RP C18 column with a mobile phase comprising metanol:0.1 % (w/ v) aqueous phosphoric acid solution in isocratic mode (80: 12, v/v) at a flow rate of 1 mL/min. Ursolic Acid was detected at a wavelength of 210 nm. The method was shown to be specific, linear in the range of 10-310 mu g/mL (R-2 = 0.999), precise at the intra-day and inter-day levels as reflected by the relative standard deviation values (less than 1.0 %), accurate (average recovery 100.17 %). The detection and quantitation limits were 0,000417 and 0,001388 mu g/mL, respectively. The method was successfully used to determine the entrapment efficiency of ursolic acid in poly(epsilon-caprolactone) nanoparticles.