in situ gel systems

Ciprofloxacin hydrochloride is a fluoroquinolone antibiotic, widely effective in the treatment of ophthalmic disorders like, corneal ulcers and conjunctivitis. In the present study, an attempt has been made to formulate ciprofloxacin hydrochloride as sustained release in situ gel systems utilizing the concept of ion- activated gelation using Gelrite alone and with sodium alginate in combination with HPMC E50 LV. Prepared formulations were evaluated for several parameters like drug polymer compatibility, viscosity, gelling and gel retention time, clarity, pH, drug content, antimicrobial efficacy, sterility and in vitro drug release. Among all the formulations, batches G3 containing 0.6 %w/v of Gelrite, A6 and A7 containing 1% w/w of sodium alginate with 0.5 and 0.75 % w/v of HPMC E50LV respectively were selected based on their gelling properties. The drug release of A6 extended upto 7 h and that of G3 and A7 extended upto 8 h. The formulations showed pseudo plastic behaviour after gelling. G3 showed better stability and clarity than the alginate formulations and was taken for further evaluations. It showed better antimicrobial efficacy when compared with standard. The mechanism of drug release from the best formulation was further evaluated. Hence the developed in situ system may be an alternative to conventional eye drops.