DEVELOPMENT AND CHARACTERIZATION OF DICLOFENAC SODIUM LOADED EUDRAGIT RS100 POLYMERIC MICROSPONGE INCORPORATED INTO IN SITU GEL FOR OPHTHALMIC DRUG DELIVERY SYSTEM

Abstract

Objective: Purpose of the study to design and formulate Diclofenac sodium (DIC) microsponges. Methods: With varied polymer: drug ratio DIC loaded microsponges were prepared with Eudragit RS100 polymer by quasi solvent diffusion method. Microsponges evaluated for particle size, entrapment efficiency, drug content, in vitro drug release, Fourier Transform Infrared Spectroscopy (FTIR), Differential scanning calorimetry (DSC) and Scanning electron microscopy (SEM). DIC loaded microsponges incorporated into ocular in situ gel to attained controlled release by microsponge and improved residence time by gelling system. Ocular in situ gel evaluated for pH, drug content determination, gelling capacity, in vitro drug release and sterility study. Results: DSER4 microsponge formulation having polymer to drug ratio 1:7 showed satisfactory production yield (68.13%), entrapment efficiency (62.86%), drug content (80.73%), requisite particle size (less than 10 µm) (7.52 µm) and in vitro release 87.94% after 6 h. Selected DSER4 formulation was incorporate into in situ gel. Carbopol 940 forms stiff gel at higher pH so used as a gelling agent, whereas Hydroxypropyl Methylcellulose E4M was used as a viscosity-enhancing agent for the formulation of in situ gel in varied compositions. In situ gel formulation IG4 showed sustained release of 76.92% till the end of 8 h and satisfactory gelling capacity so IG4 further evaluated for sterility test. Rheological studies reveal the sol-gel transition of in situ gel occur at the physiological condition to form stiff gel. Conclusion: Prepared in situ gel formulations showed sustained drug release for a period of 8 h, which is satisfactory for management of ocular pain.