Development and characterization of injectable depot forming thermoresponsive hydrogel for the sustained intrascleral delivery of Sunitinib

Age-related macular degeneration (AMD) is a potentially blinding posterior segment disease; inflammatory responses and subretinal drusen formation lead to leaky blood vessels. The current treatment method involves intravitreal injections of anti-VEGF agents, which is highly invasive and requires frequent injections administered by trained personnel. Periocular injections such as trans-/intra-scleral injections would provide a minimally invasive treatment option. The sclera is the outermost protective layer occupying 5/6th of the ocular globe. Owing to its avascular nature and self-healing ability, sclera could be the potential space for the delivery of depot forming long-acting formulations. This project focuses on the development of chitosan grafted poly(n-isopropylacrylamide) (Cs-g-PNIPAAm) gel for the sustained intrascleral delivery of small molecular weight, multiple tyrosine kinase inhibitor Sunitinib malate.