Abstract

“DESIGN, OPTIMIZATION AND EVALUATION OF SUSTAINED OCULAR DELIVERY OF LEVOFLOXACIN HEMIHYDRATE FROM pH-TRIGGERED IN-SITU GELLING SYSTEM”

Sajan Maharjan*, Amrit Khanal, Amit Shrestha, Bigyan Joshi, Shailendra Shakya, Ashwinee K. Shrestha

ABSTRACT

The aim of present work was to formulate and evaluate ophthalmic in situ gelling system of Levofloxacin hemihydrate that works in response to change in the local pH. This increase the residence time of formulation with ocular surface reducing the frequency of administration and hence achieving controlled release and greater therapeutic efficacy of the drug. Thirteen formulations of 0.5% Levofloxacin ophthalmic in situ gel were formulated using various concentration of Carbopol 940 (0.3% to 0.5%) and Sodium CMC (0.2% to 0.6%) using Minitab. pH of the formulations were adjusted within 6.0 ± 0.2 in order to achieve maximum solubility of drug as well as to avoid ocular irritation after instillation in cul de sac. The prepared in situ gels were then evaluated for visual appearance, clarity, pH, drug content, gelling capacity, rheological studies, sterility testing, antimicrobial efficacy, ocular irritation and in vitro drug release studies. The optimized formulation was developed using response optimizer in Minitab which resulted in carbopol concentration 0.4026% w/v and Sodium CMC 0.1172%w/v. The release behavior of optimized formulation was compared with conventional eye drop and the optimized formulation was evaluated for stability testing for the period of 3 months. The developed formulations were light yellow in colour, therapeutically efficacious, non-irritant, stable and provided sustained release of the drug up to eight hours’ time.

Keywords: In- situ, pH triggred, sol to gel, Levofloxacin hemihydrate, Carbopol 940, Sodium CMC, sustained release.