Assessment of taste masking of captopril by ion-exchange resins using electronic gustatory system

The objective of the study was to mask the unpleasant taste of captopril (CPT). Taste masking was achieved by complexation of CPT with a basic ion exchange resin, Dowex^® 66, using the batch method. Dowex^® 66 was used for the adsorption of CPT, and physical and chemical parameters of the CPT resinates complex were evaluated. A central composite design was used to generate the experiments for the manufacture of resinates using different process and formulation variables. In vitro dissolution studies were performed for 2 h in 0.01N HCl (pH 1.6) using USP Apparatus I. The compatibility of CPT and the resin was evaluated by Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD). The resinates were evaluated for micromeritic properties and further characterised using FTIR, DSC, and PXRD. Response surface methodology was used to determine the significance of input variables on the CPT content and release. The CPT resin ratio was found to have a significant impact on content of the resinates and on CPT release. The formulations were also studied for taste masking ability by means of an electronic gustatory system - electronic tongue.