Fabrication and evaluation of taste masked resinate of risperidone and its orally disintegrating tablets.

The present investigation was undertaken to design a simple, rapid, cost effective and highly efficient process to fabricate a tasteless complex of risperidone using ion exchange resin (IER), evaluate the molecular properties of the resinate and finally incorporate it into orally disintegrating tablets (ODT). The resinate formation using Amberlite IRP64, was confirmed using the characterization methods: Fourier transform-infrared (FT-IR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The maximum loading efficiency achieved was 99.72+/-0.16% in 1 : 4 (drug : resin weight) ratio at pH 6.0, temperature at 22 degrees C in a period of 1.5 h using ethanol : water (1 : 1, v/v) as the complexation medium. The complex was compressed into orally disintegrating tablet. The drug release from the complex was about 2.5% in 120 s in 5 ml of pH 6.8 phosphate buffer which has been used to mimic the salivary fluid volume and pH. Dissolution studies using 500 ml of 0.1 N HCl at 50 rpm in USP Apparatus II released 92% in 5 min, indicating complete drug release from the complex in the stomach. Resinate was tasteless while the fabricated ODTs were pleasantly tasting without any bitterness of drug as confirmed by the taste panel.