INTERACTION OF TIARAMIDE HYDROCHLORIDE WITH AMBERLITE RESINS: CHARACTERIZATION OF THE INTERACTION AND MODULATION OF THE RELEASE THROUGH MICROENCAPSULATION OF THE PREPARED RESINATES

Tiaramide HCl (TAM), a basic NSAID, has high water solubility and short biological half life. The study was undertaken to prolong TAM's activity. TAM resinates were prepared by a batch process and using two resins, namely Amberlite IRP-69 (RI) and Amberlite MB-1 (RII). The resinates (RI/TAM & RII/TAM) were examined by differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), infrared (IR) spectrometry and scanning electron microscopy (SEM). A modified emulsion solvent evaporation method was used to produce TAM-resinates coated with cellulose acetate butyrate (CAB) for more drug retardation. The microcapsules were examined using SEM. The results from DSC and XRD showed that the molecular state of the drug in the resinates changed to become amorphous instead of its original crystalline form. The IR spectroscopy revealed the presence of an interaction between the drug and resin. The dissolution behavior for the resinates in 0.1 N HCl or phosphate buffer (pH 7.4) was compared. TAM release was affected by the dissolution medium and resin type and was slower than that from drug powder or physical mixture. TAM release from microcapsules was slower than the uncoated resinates. Additionally, the anti-inflammatory activity, using carrageenan–induced rat hind paw edema, displayed prolonged pattern in comparison with uncoated resinate or free drug