Introduction: The main purpose of the research was to develop, optimize and characterize tobramycin sulphate loaded chitosan nanoparticles based gel in order to ameliorate its therapeutic efficacy, precorneal residence time, stability, targeting and to provide controlled release of drug.
Methods: Box-Behnken design was used to optimize formulation by 3-factors (chitosan, STPP and tween 80) and 3-levels. Developed formulation was subjected for characterizations such as shape and surface morphology, zeta potential, particle size, in-vitro drug release studies, entrapment efficiency of drug , visual inspection, pH, viscosity, spreadability, drug content, ex-vivo transcorneal permeation studies, ocular tolerance test, antimicrobial studies, isotonicity evaluation and histopathology studies.
Results: Based on evaluation parameters, the optimized formulation showed particle size 43.85 ± 0.86 nm, entrapment efficiency 91.56% ± 1.04, PDI 0.254. Cumulative in-vitro drug release was up to 92.21% ± 1.71 for 12 hours and drug content was found in between 95.36% ± 1.25 to 98.8% ± 1.34. TEM analysis unfolded spherical shape of nanoparticles. TS loaded nanoparticulate gel exhibited significantly higher transcorneal permeation as well as bioadhesion when compared with marketed formulation. Ocular tolerance was evaluated by HET-CAM test and formulation was non-irritant and well tolerated. Histopathology studies revealed that there was no evidence of damage to the normal structure of the goat cornea. As per ICH guidelines stability studies were conducted and were subjected for 6 months.