Ion-sensitive in situ gelling solution containing tobramycin for management of ocular infections

Stimuli Sensitive Drug Delivery Systems have become a promising approach in the field of drug delivery and contributed by use of polymers which are able to deliver drug in response to change in surrounding environmentsuch change in temperature, pH, ionic strength, enzymes or biomolecules. ocular drug delivery often encounters the problems of low instillation quantity of medicament and also poor residence of drug in the ocular region which decreases the efficiency of the treatment. An ineffective antibacterial treatment would lead to bigger problems like resistance. Hence the current study was undertaken to formulate Ion-sensitive in-situ ophthalmic gelling solution of Tobramycin using Sodium alginate as ion sensitive polymer. The batches were prepared by using 3² factorial designwhere sodium alginate and HPMC K4M were selected as independent variables. The evaluation of various dependent parameters like clarity, viscosity, mucoadhesion and in vitro release was done. The formulations were ensured to be sterileand isotonic. The in-situ gelation occurred when the formulation came in contact with tear fluid with good mucoadhesion and gel strength. The Tobramycin drug release study showed release over a period of more than two hours. In vivo eye irritation test was done on white rabbits.