DESIGN AND DEVELOPMENT OF FLOATING MICROSPHERES OF OFLOXACIN

In the present study design and development of floating microspheres of ofloxacin. During the Preformulation studies it is found that the organoleptic properties of Ofloxacin comply as reported. Pale yellow, bitter, odorless, amorphous powder of ofloxacin was soluble in water, 0.1N HCl and Phosphate buffer (pH 6.8) and freely soluble in ethanol and methanol. Melting point was observed at 156⁰C and λ_max at 296nm. Standard calibration curve was prepared using concentration range 5- 25 ug/ml and linearity equation as y = 0.032x – 0.003 with R² = 0.998. Partition coefficient was found 0.989. Five different formulations were prepared by o/w emulsion solvent evaporation method using different concentration of Ethyl Cellulose EC) and fixed amount (100mg) of ofloxacin and tween-80 (1%). Evaluation of prepared floating microsphere were found yield between 91.69 to 95.43%, mean particle size between 463 to 676 µm and encapsulation efficiency between 78.6 to 98.2%. On the basis of various parameter of evaluation of floating microspheres formulations, F-4 has greater yield 95.43 % but its encapsulation efficiency was lower 74.6. F-1, F-2, F-4 and F-5 were possessed poor mircomeritic properties e.g. Carr’s Index 39.65, 37.65, 29.31 and 30.44% respectively, Hausner’s ratio 1.657, 1.604, 1.415 and 1438 respectively and angle of repose (θ) 31, 35, 28 and 29 respectively that indicates irregular shape, improper size distribution and poor to very poor flow properties of the prepared microsphere. Hence, all formulations except F-3 were not suitable for further investigation. F-3 microsphere batch possessed yield (91.69%), particle size (676 µm), encapsulating efficiency (98.2), Carr’s Index (5.08%), Hausener’s ratio (1.054) and also drug release was 97.913 %. Stability studies for 30 days was performed on three different temperatures (4, 25 & 45^oC) and found that no significant variation in % drug release of optimized floating microspheres batch F-3 during whole study.            

KEYWORDS: Residence time, Sustained release, therapy, drug release, bioavailability