STATISTICAL OPTIMIZATION AND EVALUATION OF IN SITU GEL FOR THE OCULAR DELIVERY OF CROMOLYN SODIUM

Objective: The study aimed to develop and optimize cromolyn sodium-based ocular in situ gel to improve the ophthalmic contact period and provide sustained drug release for treating allergic conjunctivitis. Methods: Formulations were prepared using sodium alginate and HPMC K4M (Hydroxypropyl Methylcellulose) polymers and were characterized and evaluated for viscosity, gelling time, in vitro drug release, and optimized using a factorial 3² DOE design (Version 11; Design Expert® software). The resulting cromolyn sodium-based formulation was tested for hyperemia and eye-scratching behavior in Wistar albino rats. Results: Increased polymer concentrations resulted in higher viscosity with decreased gelling time and in vitro drug release. The optimized formulation achieved a viscosity of 15.350 cps, a gelling time of 55.137 s, and sustained drug release of 92.61% over 12 h. The in vivo pharmacodynamic study of the optimized formulation showed a significant decrease in the frequency of eye-scratching behaviour (7.525) at a significance level of (**p<0.01) and hyperemia (1.125) (***p<0.001, *p<0.05) compared to negative and positive control indicating that the developed in situ formulation improved the drug's therapeutic effectiveness by extending its duration within the cul de sac. Conclusion: In light of these findings, this optimized cromolyn sodium in situ gel holds promise as a viable alternative to conventional eye drops.