Abstract :
Opthalmic In-situ gels refers to polymer solution which can be administered as liquid and undergoes a phase
transition to semisolid gel upon exposure to physiological environment i.e., pH, Temperature, ions in the lachrymal
fluid. The poor bioavailability and therapeutic response exhibited by conventional ophthalmic solutions due to rapid
precorneal elimination of the drug can be overcome by the use of in situ gel system that are instilled as drops into
the eye and undergo a solâ€gel transition in the cul-de-sac. Fungal keratitis is a serious disease that can lead to loss
of vision if not diagnosed and treated effectively. Itraconazole is a triazole compound effective against Fungal
keratitis. Because of poor bioavailability of Itraconazole opthalmic solutions, we formulated itraconazole
opthalmic in situ gels by pH triggered, ion activation and temperature modulation methods. Total nine formulations
have been prepared by using different concentrations of gelling agents i.e., carbopol 934 as pH triggered polymer,
sodium alginate as ion activated polymer and poloxamer 407 as temperature triggered polymer. All the
formulations contain Hydroxy Propyl Methyl Cellulose (HPMC) as viscosity enhancer, sodium chloride as tonicity
adjusting agent, benzalkonium chloride as preservative. All the formulations were evaluated with respect to clarity,
pH, gelling capacity, viscosity, drug content and in-vitro drug release. Among all the formulations, F4-F6
containing sodium alginate as gelling agent exhibited maximum drug release of 96.55±0.56% for prolonged period
of time upto 8hrs. These formulations also shown optimum results for all the evaluation parameters. Hence
formulations F4, F5 and F6 prepared by ion activation method were selected as optimized formulations. So from the
present study, we concluded that the Itraconazole opthalmic in situ gels will be promising approach to overcome the
drawbacks of conventional opthalmic solutions.
Keyword :
In Situ Gels, Carbopol 934, Poloxamer 407, Sodium Alginate, Itraconazole.