155DEVELOPMENT OF A CASSIA FISTULA NANOGEL FORMULATION AND EVALUATIONCassia fistula nanogel formulations as topical drug delivery. With their nanosized pores, nanogels have controlled drug release, enhanced bioavailability, and enhanced therapeutic efficacy with skin-related uses. Cassia fistula (antimicrobial, anti-inflammatory and antioxidant) is a good candidate to form nanogel. Its active phytochemicals however, flavonoids and anthraquinones, have poor solubility and bioavailability. The extract was obtained using soxhlet extraction and incorporated into nanogel formulations by emulsion - solvent diffusion procedure. The formulations were compared on the basis of physicochemical properties, pH, viscosity, and spreadability and in vitro drug release. A formulation containing Carbopol-1%, Xanthan gum-3 and SCMC-4 (optimized as F7) demonstrated the best drug release (99.52) and zero-order release pattern during 12 hours. Entrapment efficiency was high and the nanogel was stable at 4°C. The use of Scanning Electron Microscopy (SEM) ascertained consistency in terms of nanoparticle size and spherical morphology, which also aided stable and consistent drug release. The antibacterial effect of the formulation was validated with great inhibition of E. coli. The researchers come up with a conclusion that nanogels made out of Cassia fistula hold promise of prolonged topical drug delivery, especially in the case of antibacterial agentsmaryvictoriya2002@gmail.comResearch1522025 Cassia Fistula, Nanogel, Drug Delivery, Sustained ReleasPeddereddla Mary Victoriya,Purushothaman MKLR Pharmacy College, Paloncha, Bhadradri Kothagudem, Telangana-507511, India,KLR Pharmacy College, Paloncha, Bhadradri Kothagudem, Telangana-507511, India