Design and development of novel bioadhesive niosomal formulation for the transcorneal delivery of anti-infective agent:In-vitro and ex-vivo investigations

摘要

Gatifloxacin eye drops are frequently used in eye infections.However such formulations have a major drawback i.e.short duration of action and usually require 4e6 times installations daily.A chitosan coated niosomal formulation of gatifloxain was purposed to show a longer retention time on eyes and subsequent reduction in dosing frequency.Vesicles were prepared by solvent injection method using cholesterol and Span-60.An extensive optimization of formulation was done using different ratios of cholesterol,Span-60 and drug,revealed NS60-5(cholesterol:span-6050:50 and drug content of 20 mg)to be the optimized niosome formulation.NS60-5 had shown a highest entrapment efficiency of 64.9±0.66%with particle size 213.2±1.5 nm and zeta potential34.7±2.2 mV.Optimized niosomes were also coated with different concentrations of chitosan and evaluated.Permeation studies had revealed that optimized niosomes(86.77±1.31%)had increased the transcorneal permeation of Gatifloxacin more than two fold than simple drug solution(37.19±1.1%).Longer retention potential of the coated niosomes was further verified by fluorescence microscopy.Study revealed that simple dye solution got easily washed out with in 6 h.The uncoated niosomes(NS60-5)showed a longer retention(more than 6 h),which was further enhanced in case of coated niosomes i.e.CNS60-1(more than 12 h).Antimicrobial studies had shown the better efficacy of CNS60-1(zone of inhibition)when compared to marketed formulation.The final chitosan formulation was found to have shown better ocular tolerability as demonstrated by corneal hydration test histopathology investigations.