A review of novel nanoformulations for treatment of dry eye disease and ocular surface inflammation

Dry eye disease (DED) is a multifactorial condition frequently encountered in ocular disorders. DED not only causes ocular discomfort but also leads to damage to the cornea and conjunctiva. The topical route of drug administration is commonly used for treating ophthalmic diseases; however, its major limitation is the low ocular drug bioavailability, which typically amounts to less than 5%. This limitation arises due to the multiple permeation barriers between the tear film and the inner layers of the cornea, which hinder the achievement of therapeutic drug concentrations in ocular tissues. Researchers have significantly advanced in developing practical and safe drug delivery systems to address these challenges. These innovations have improved the penetration of medications through ocular barriers, enabled targeted delivery to specific cells and tissues, and enhanced the retention time, solubility of hydrophobic drugs in aqueous solutions, and overall bioavailability. Encapsulating drugs within nanoparticles has protected against degradation, further improving therapeutic efficacy. This review aims to explore various nanoformulations (e.g., liposomes, niosomes, suspensions, and emulsions) designed to enhance the ocular bioavailability of topically administered medications. A comprehensive DED inflammation overview focuses on the disease's etiology, clinical manifestations, and therapeutic approaches. It is anticipated that the development of advanced medication delivery systems will lead to improved management of DED shortly. The advancements discussed here may pave the way for creating novel, highly effective, and essential ocular nanosystems.