Londhe R.A4. Phalke P.L

The field of ocular drug delivery is one of the most challenging and interesting field for pharmaceutical scientist. In ophthalmic in situ gels various polymers are used. Generally hydrogels are used. These polymers will increase solution viscosity the field of ocular drug delivery is one of the most challenging and interesting field for pharmaceutical scientist. From last 10 to 20 years the field has been significantly improved1. Due the site of delicacy and the many restrains of the site of application caution has to be taken during formulation of new product2. According to physiology of eye this organ is impermeable to foreign substances. It is difficult to formulation to cross the protective barriers of eye so that drug reaches to site of action in sufficient concentration.1 Novel drug delivery systems aimed to overcome the biological barrier which can obstruct efficient ocular drug delivery.3 Crossing protective barrier without damaging the permanent tissue is major challenge to formulator during formulation. Some common diseases which are cured by topical drug delivery are blepharitis, conjunctivitis, keratitis, trachoma, glaucoma etc4. The major disadvantages of conventional formulation such as solutions, suspensions, emulsions, ointments etc. are poor bioavailability, increased precorneal elimination, high variability in efficacy respectively.5 Because of convenience and safety for ophthalmic chemotherapy optical application of drug is most preferred formulation.