Prolonged delivery of ciprofloxacin hydrochloride from hydrophilic ocular inserts

Ocular inserts were developed with prolonged release of drug and minimum swelling within cul-de-sac using ciprofloxacin (CPF) hydrochloride as a model drug. The ocular inserts were fahricated with sodium alginate films loaded with drug and then treated with calcium chloride. A 4% w/v solution of calcium chloride and an exposure of 15 s to this solution was found to be the optimum treatment combination of inserts. Four types of inserts were produced: type-I contained CPF hydrochloride and alginate, type-II contained CPF crystals and alginate, type-III contained CPF hydrochloride inalginate and hydroxypropylmethylcellulose (HPMC) matrix and type-IV contained CPF crystals entrapped inalginate and HPMC matrix. In vitro release profile of drug from the inserts followed Higuchi and first-order kinetic models. Longer duration for 90% drug release were obtained from types-II and IV inserts than from types I and III, although type III had a longer duration than type-I inserts. In vivo studies were carried out in rabbit eyes by measuring the tear concentrations against time. From the pharmacokinctic parameters obtained types II and IV were found to prolong the duration of action more than 2 days while types I and II inserts the duration of action lasted for about 1.5 days.