Cross-linked chitosan-dextran sulphate vehicle system for controlled release of ciprofloxaxin drug: An ophthalmic application

The major challenge associated with conventional eye-drop is the rapid drug loss due to precorneal defence barrier. In this context, controlled-release system of ciprofloxacin-conjugated chitosan (CS)-Dextran sulphate (DS) nanoparticles (NPs) have been synthesized, to increase the bioavailability. The formulated drug delivery vehicle was evaluated for its therapeutic value in the simulated tear fluidat pH 7.4. Ophthalmic microbes were tested with this formulation, to confirm the drug efficacy; which showed conducive therapeutic values of both MIC and MBC. Ocular irritancy test was performed using HET-CAM test, which showed that the CS-DS system did not yield any vascular response, offering it to be a non-irritant to the ocular surface. The release studies showed monotonous controlled-release for duration of 21 h. A fine cross-linking between CS and DS has been demonstrated to form CS-DS NPs and their interaction with drug has been evaluated using conventional characterization tools.

Through this manuscript we communicate our work done to synthesise a vehicular system for controlled release of a specific drug, Ciprofloxacin for ophthalmic application. Ciprofloxacin is an ocular drug, mainly used in the form of eye-drop, which suffers from a standard demerit of commensurate wastage of drug due to eye irritancy and tear flow. This is mainly due to drug loss at precorneal barrier. In this context, through this manuscript, we discuss a system of cross-linked particles of chitosan (CS)-Dextran sulphate, through which the drug is released in controlled fashion. Particle size analysis, structural chemistry, drug loading percentages have been carefully brought out using conventional characterization tools. The cationic polymer chitosan was cross-linked with anionic dextran sulphate sodium which significantly increased the ciprofloxacin loading efficiency (83%) and sustained release of ciprofloxacin at 21 h. The formulated drug delivery vehicle has been evaluated for its therapeutic value in the simulated tear fluid at pH 7.4. Ophthalmic microbes were tested with this formulation, to confirm the drug efficacy; via the derived values of MIC and MBC. Ocular irritancy tests have been performed using HET-CAM test. The release studies showed an initial burst release and further controlled-release for duration of 21 h.214