Formulation and In-Vitro Evaluation of Ocular Ciprofloxacin-Containing Minitablets Prepared with Different Combinations of Carbopol 974P and Various Cellulose Derivatives

The aim of this study was preparation and evaluation of ciprofloxacin-containing minitablets for ocular use, in an attempt to obtain prolonged and controlled drug release to the anterior eye segment. Following initial studies on ciprofloxacin powder, it was formulated into ocular minitablets. For this purpose, ciprofloxacin along with various amounts of different sustained release cellulose derivatives (HPMC, Na CMC, HEC and EC), Carbopol 974P, solubilizer and lubricant were directly compressed into minitablets, using concave 3 mm diameter punches. All the prepared formulations were evaluated in terms of physicochemical tests, including uniformity of weight, friability, crushing strength, water uptake and in-vitro drug release studies. It was found that the type and amount of cellulose derivatives used, can influence the rate of drug release. The finally selected formulation (B3) contained ethyl cellulose, Carbopol 974P, mannitol, sodium stearyl fumarate and ciprofloxacin, which showed more than 80% drug release over a period of 5h, and complied well in all the physicochemical tests conducted. Based on kinetic studies, formulation B3 was found to best fit the zero order equation. However, the Higuchi and Hixson-Crowell models also showed a good fit. Hence, overall formulation B3 was chosen as the best formulation.