Dexamethasone Loaded Electrospun Nanocomposite Ocular Insert: In-vitro Drug Release and Mechanical Assessment

Abstract

Background: Dexamethasone is currently available as suspension for the treatment of anterior ocular inflammatory diseases that are given through eye drops. Upon topical delivery by eye-drops, less than 5% of the drug gets absorbed when applied topically as eye drops. The major portion of administered drug either comes out from the eye or gets subjected to nasolacrimal drainage resulting in poor bioavailability. Objective: The present study is aimed at developing polymeric ocular insert containing dexamethasone as a drug by employing the use of electrospinning technique. Methods: Dexamethasone (0.1% w/v) loaded electrospun sheet was also made using 10% w/v EC: HPMC: PEO (60:20:20) in solvent system of ethanol: water (90:10) at optimized electrospinning parameters of 12kV with a flow rate of 0.8mL/hr and distance of 20 cm between tip and collector. Results: The prepared nanocomposite insert was characterized for DSC and FTIR-ATR spectroscopy revealing no physical-chemical interaction between drug with polymers. The thickness of the electrospun sheet was found to be 270±0.02 μm and % drug content was found to be 0.43±0.01% w/w. The release profile showed that around 95% drug was released in 48 hrs. This release profile showed the prepared drug-loaded electrospun ocular insert was best suitable for once-a-day delivery. Assessment of mechanical properties like young’s modulus, tensile strength, and % elongation showed that the prepared insert can be handled easily without any breakage or damage. Conclusion: Upon delivery in conjunctival sac, this is best suitable for once-a-day delivery. The developed electrospun insert, consisting of a unique polymer composite of biodegradable polymers, avails the benefits of nanofibers imparting prolonged release and this novel formulation overcomes the limitations of conventional therapies. This reduces the dosing frequency and improves patient compliance.