An intraocular lens-based biodegradable drug delivery system for the treatment of post-cataract inflammation

Prolonged inflammation after post cataract surgery causes inconvenience in patients. Inadequate treatment results in loss of vision to around 30000 patients/year in India. Currently, treatment is topical administration of eye drops. We propose a biodegradable drug delivery system (DDS) bound to intraocular lens (IOL) haptic which combines surgery and post-operative care. To overcome the disadvantages of topical administration the polymer poly lactic-co-glycolic acid (PLGA) is designed as a thin film strip with Dexamethasone (DEX) to release therapeutic amount of drug over a period of 4 to 6 weeks. The study involved two PLGA co-polymer ratios 75:25 and 50:50 with different polymer:drug ratios were used to study the release of drug over a period of 30 days. PLGA75:25 (dimensions: 30x3mm; thickness 0.073mm) loaded with 158μg DEX released around 3.5μg in the first 5 days and then 0.52μg/day for remaining 25 days. The DDS was characterized by Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Differential Scanning Colorimetry (DSC). In vitro drug release kinetics were mathematically modelled using zero order, first order, Higuchi, Korsmeyer-Peppas and Hixson Crowell model and then fit to experimental data. Korsmeyer-Peppas model and Higuchi model best fit the experimental data.