FORMULATION AND EVALUATION OF BIODEGRADABLE MICROSPHERE HYDROGEL FOR OCULAR DELIVERY OF METRONIDAZOLE

Abstract

The objective of the present investigation was to explore the hydrogel microspheres loaded with metronidazole to obtain controlled release for ocular delivery. The FTIR spectra of pure drug and the drug excipient mixture revealed no chemical interaction. Metronidazole loaded hydrogel microspheres were prepared using Chitosan/Pluronic F68 blend and emulsion crosslinking method. MHM7 with blend ratio 3.33:1 exhibited the highest encapsulation efficiency (77.1505%) whereas the lowest encapsulation was witnessed in the formulation MHM3 (34.71%) which has a blend ratio of 15:1. The particle size ranged from 26.96 µm for MHM3 to 134.8 µm for MHM7. The microspheres exhibited negative zeta potential and the value was found to be -18.1 mV for MHM7. MHM3 exhibited the highest water uptake (350.5 %) whereas MHM7 exhibited the lowest water uptake (117.5 %).  MHM7 released around 59.54% drug after 24 h. Formulation MHM4 was also able to control the release to a great extent with 67.37% drug released at the end of 24 h but it exhibited a lower encapsulation efficiency of 61.771%. Hence MHM7 was considered to be the most optimized formulation. The release of metronidazole from MHM7 followed Higuchi mathematical model suggesting Non-Fickian diffusion.