Insights into ocular therapeutics: A comprehensive review of anatomy, barriers, diseases and nanoscale formulations for targeted drug delivery

Abstract

Ocular drug delivery systems play a critical role in the treatment of various eye diseases via ensuring targeted and efficient delivery of therapeutic agent. The complex anatomy and physiological barriers of the eye poses challenges for effective drug delivery. Conventional methods, such as eye drops, often face challenges like low bioavailability and a short retention time on the ocular surface. Researchers have actively contributed to the development of novel ocular drug delivery methods in an effort to overcome these limitations and improve therapeutic efficacy while reducing the potential side effects. Nanotechnology based carriers (lipid based, polymeric nanosystems etc.) are well known for their potential to encapsulate hydrophilic and lipophilic drugs, prolong drug release, enhance ocular permeability and bioavailability, improve patient compliance, and reduce side effects. This promotes reduction in frequency of dose administration as well as patient adherence to treatment regimens. This comprehensive review explores the intricate interplay between ocular diseases and advancing drug delivery systems designed to enhance therapeutic outcomes, discussing their benefits, addressing challenges, and exploring potential future developments. The review also explores various ocular diseases such as glaucoma, cataracts, and retinal disorders etc., their causes, symptoms, and diagnostics, emphasizing the importance of understanding barriers like the cornea and blood-ocular barriers. Additionally, this review explores various nanoscale platforms and their characterization approaches, offering insights into strategies for enhancing ocular bioavailability. The ongoing evolution of ocular drug delivery systems holds significant promise for enhancing the treatment of diverse eye diseases.