Tinidazole loaded Oil entrapped floating beads prepared by the emulsion gelation method were optimized for polymer: cross linking agent ratio (sodium alginate/ Calcium chloride),oil selection (olive oil and castor oil), oil concentrations (10%, 20% and 30% w/w) and drug: polymer (D: P) ratios (1:1, 2:1 and 3:1).The beads were designed to improve drug concentration in the gastric mucosa from oral preparations compared with that from many commercially available and modified release products, have been investigated as a possible gastro-retentive dosage form. The prepared beads were evaluated for diameter, surface morphology, encapsulation efficiency, buoyancy and in-vitro release. The calcium alginate beads remained buoyant for times in excess of 12 h, and the density of the calcium alginate beads was <1.000 g cm. The results clearly indicated that the percentage of oil plays an important role in controlling the floating of oil-entrapped Calcium alginate beads. In vitro drug release demonstrated sustained release of Tinidazole for 8 h, which best fitted the Higuchi model with n < 0.5. Calcium alginate beads containing 20% oil and 2:1 D: P ratio showed an optimum DEE (92.44 %). Scanning electron microscopy revealed that externally the calcium alginate beads were spherical in shape, and internally, air filled cavities were present thereby enabling floatation of the beads. The characterisation studies showed that the calcium alginate beads could be considered as a potential gastro-retentive dosage form for local as well as systemic drug delivery.
