Design and optimization of ocular inserts for prolonged delivery of ciprofloxacin hydrochloride

Ocular inserts containing ciprofloxacin hydrochloride (CPF) as a model drug were developed by optimization of design applying ANOVA. The parameters of optimization were taken as the concentration of calcium chloride solution and time of exposure of the treatment. Out of the four formulations studied, types III and IV contained hydroxypropylmethylcellulose (HPMC) whereas types I and II were developed without HPMC. Type I and III contained CPF as the soluble hydrochloride salt while in types II and IV CPF is present in crystal form. In vitro dissolution studies with the four formulations showed that time of 90% drug release for types II and IV were 23.8 ± 0.2 and 25.8 ± 2.6 h, respectively, whereas the same for types I and III were 8.9 ± 0.6 and 16.6 ± 1.5 h. In vivo studies on all the formulations in the rabbit eye revealed that tear concentrations of CPF lasted for more than 2 days with types II and IV inserts. All the formulations showed excellent retention properties in the cul-de-sac of rabbit eyes with almost no irritation.