Development of taste masked levofloxacin oral suspension using ion exchange resinates

In the present work, taste masked resinates of levofloxacin using Tulsion-335, an acidic cation ion exchange resins were used to develop its oral suspension formulations. The drug resin complexes were prepared by batch process by taking drug to resin ratios of 1:1, 1:2, 1:3 and 1:4. The techniques of differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the drug resinates. The ratio of 1:4 was found to be effective for masking the bitter taste of the drug as confirmed by the taste studies. Dissolution rate studies of the taste masked drug resin complexes were carried out in Phosphate buffer pH 6.8 (Salivary pH). Dissolution rate studies in phosphate buffer pH 6.8 showed that more than 90% of pure drug was dissolved in 5 minutes, while in the same period the dissolution of levofloxacin from drug resin complex in 1:4 ratio was below 40%. This was the possible reason for reduction of bitter taste of drug. Finally the resins were used for the preparation and evaluation of oral suspension of the bitter drug. The developed oral suspension was found to be better in taste when compared with marketed suspension of levofloxacin.