in-situ ocular gels of Ketorolac Tromethamine

In-situ gelling systems are viscous polymer-based liquids that exhibit sol-to-gel phase transition on the ocular surface due to change in a specific physico-chemical parameter like ionic strength, temperature or pH. A major problem in ocular therapeutics is the attainment of optimal drug concentration at the site of action, which is compromised mainly due to pre-corneal loss resulting in only a small fraction of the drug being ocularly absorbed. The effective dose administered can be altered by increasing the retention time of medication into the eye by using in situ gel forming systems, thereby preventing the tear drainage. The aim of the present investigation is to prepare and evaluate novel in situ ocular gelling system (Thermo-reversible, pH induced, and ion activated in situ gelling systems) of Ketorolac tromethamine. Polymers like Pluronic F 127, Methyl cellulose, Carbopols, Sodium alginate, Xanthan gum, HPMC E50LV were used for the preparation of in situ gelling systems of Ketorolac tromethamine. The formulations were evaluated for clarity, pH measurement, gelling capacity, drug content estimation, rheological study, in vitro drug release, ocular irritation studies (as per draize test) and ex-vivo corneal permeation studies using isolated goats cornea. The developed formulations showed sustained release of drug with increased residence time. The formulations were found to be non-irritating with no ocular damage. These in situ gelling systems (Thermo-reversible, pH induced, and ion activated in situ gelling systems) may be a valuable alternative to the conventional eye drops.