In vivo and in vitro taste masking of ofloxacin and sustained release by forming interpenetrating polymer network beads

Drug-resin complexes (DRCs) of ofloxacin and ion-exchange resins (IERs) were prepared in different ratios of drug/IERs, that is, 1:1, 1:2 and 1:4 (w/w) and investigated for taste masking by in vivo and in vitro release studies. Human volunteers graded AD1:4 (DRC) as tasteless with an average value of 0.3 +/- 0.03 and in vitro study showed that AD 1:4 released only 1.70 +/- 0.86% of drug at salivary pH within 30s. Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (P-XRD) and differential scanning calorimetry (DSC) studies of AD 1:4 showed the change in the morphology of the drug, that is, from crystalline phase to amorphous phase during complex formation. The release of drug from AD 1:4 was completed within 30min at gastric pH 1.2 and to extend the release time of drug at gastric pH, it was entrapped with different biopolymers, such as sodium alginate (SA) and sodium carboxymethyl cellulose (SCMC), in the presence of ferric chloride and glutaraldehyde (GA) to form interpenetrating polymer network (IPN) beads. FTIR studies revealed that IPN beads were crosslinked with Fe(3+)and GA. The release of drug at gastric and intestinal pH was 14.53 +/- 1.52% and 65.86 +/- 1.29%, respectively, for a contact time of 10h. The kinetics release study shows fickian diffusion for ionically crosslinked beads and zero-order release for GA crosslinking beads.