Effervescent tablet formulation for enhanced patient compliance and the therapeutic effect of risperidone

Risperidone is a poorly water soluble atypical antipsychotic drug. This work investigated the potential of developing risperidone effervescent tablets to facilitate drug administration and mask drug taste. The solid dispersion technique was selected to improve drug solubility due to its ease of scaling up, reproducibility and affordable cost. Thirty formulas were prepared adopting a 5(1).2(1).3(1) full factorial design. Trehalose, Inulin, pregelatinized starch, carboxymethylcellulose sodium and Eudragit E100 were used as hydrophilic carriers at different ratios. Rotovap, lyophilization and the kneading-oven were applied as solvent evaporation techniques. Differential scanning calorimetry, X-ray powder diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy showed that the drug was present as amorphous material entrapped within the carrier matrix. Eight tablet blends were prepared using different effervescent mixture ratios with or without binder and lubricant/glidant mixture. All of the blends had acceptable flowability, acceptable effervescence times and immediate drug release that could not be achieved by any of the control formulas. The formula of choice contained 40% effervescent mixture, 5% starch, 1% boric acid, 1% aspartame and sufficient lactose. The relative bioavailability (RB) of risperidone from this formula was 161.41% with a significantly higher extent of absorption compared to the market conventional tablets. This formula may be promising in improving patient compliance and drug efficiency.