Abstract
Nanotechnology has surmounted various application in drug delivery despite divergent challenges in physical, surface properties and reproducibility of preparation method. Ultrasensitive analytical methods are highly demanded in order to monitor the very minute drug concentrations obtained during drug release studies as a result of the extensive prolongation in the release rate achieved in all nano-particulate drug delivery systems. A simple, rapid, sensitive, reversed-phase isocratic RP-HPLC method for determination of valsartan (Val) was developed. The method was applied for quality control tests including entrapment efficiency and drug release for Val-loaded nano-structured lipid carriers (NLC). The method was carried out using Eclipsed XBD column (Agilent -PN 993967) C18 (150 mm x 3.0, 5 mu m particle size) with mobile phase composed of acetonitrile: phosphate buffer (60:40) at pH 3.6, 0.01 M. The flow rate was set at 1.0 ml/min and effluent was detected at 273nm. The retention time of valsartan was found to be 2.910 minute. The method was validated for specificity, accuracy, precision, linearity, and limit of detection, limit of quantification and robustness. Limit of detection (LOD) and limit of quantification (LOQ) were found to be 6.0 and 25 ng/ml respectively. The calibration curve was linear in the concentration range of 39.06-2500 ng/ml with coefficient of correlation 0.9992. The percentage recovery for Val was found to be 99.86-100.06 and the % RSD was found to be less than 2 %. The proposed method was free from any interference and successfully applied for quantitative determination of valsartan in lipid-based nano-particulate systems.