Abstract

The aim of this study was to develop and validate a rapid and sensitive reverse-phase high performance liquid chromatography method for the quantitative determination of zoledronic acid in nanoparticles. The mobile phase was a mixture of methanol (30%) and 7 mM tetra butyl ammonium hydrogen sulphate, 2 mM di-sodium hydrogen orthophosphate and sulphate and 8 mM di-potassium hydrogen orthophosphate (70%), pH adjusted to 3 with trifluoroacetic acid. C18 column was used as a stationary phase. The flow rate was maintained at 1 ml/min. The detection of the constituents was done at 215 nm using an ultraviolet detector. Method validation was executed according to the International Conference on Harmonisation guidelines. The retention time of zoledronic acid was 3.27±0.03 min (n=6). The assay was linear over the concentration range of 200-800 μg/ml. The proposed method was sensitive with the limit of detection and limit of quantification values equal to 200 and 800 μg/ml, respectively. The method was accurate with percent mean recovery from 99.01±1.31 to 100.80±0.094% and precise as percent relative standard deviation values were less than 1%. The method was successfully applied for the estimation of zoledronic acid loading efficiency on hydroxyapatite nanoparticles and in vitro zoledronic acid release profile analysis in hydroxyapatite-based nanoparticles.