Quantitative determination of the non-entrapped chlorothiazide in the presence of liposomes using differential pulse polarography

Abstract

Differential Pulse Polarography (DPP) was used for the quantitative determination of the free and adsorbed (non-entrapped) chlorothiazide (CHT) in the presence of liposomes. It was found that CHT polarographic signal depends both on the concentration of multilamelar (MLV) liposomes, due to its adsorption on the liposomal surface, and on their size. Calibration plots of CHT concentration versus current density, at pH 7.4, in the presence of different liposomes concentrations were constructed. Based on these curves the non-entrapped chlorothiazide was determined. Results were compared to those obtained from the application of conventional procedure i.e. chromatographic separation of CHT from liposomes followed by UV spectrophotometric determination. Both techniques were found to be comparable with respect to their accuracy, with a relative error of 0.47%. Determination of the drug using DPP was faster.