In situ fast gelling formulation of methyl cellulose for in vitro ophthalmic controlled delivery of ketorolac tromethamine

The development of an in‐situ fast gelling vehicle for ophthalmic drug delivery based on methylcellulose (MC) was studied. The gelation temperature of 1 % MC was 59°C. Additives such as fructose and sodium citrate tribasic dihydrate (SC) were added in different proportions to reduce the gelation temperature of MC from 59°C to the physiological temperature i.e. 37°C. With the variation of fructose concentration from 2 to 10% at constant 1% MC concentration, the gel temperature was reduced from 59 to 54°C. To reduce the gelation temperature of MC further, SC was added in the system where the concentration of MC (1%) and fructose (10%) were kept constant. It was observed that with the variation of SC concentration from 1 to 5%, the sol–gel transition temperature was further lowered from 54 to 32°C. The gel temperature of all the combinations was measured by test tube tilting method and followed by UV–vis spectroscopy. The developed formulation corresponding to gelation temperature 32°C provided sustained release of Ketorolac Tromethamine (KT) over a 9 h period. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009