Drug Delivery Challenges and Current Progress in Nanocarrier-Based Ocular Therapeutic System

Area of Science:

• Ophthalmology
• Pharmaceutics
• Biomaterials

Background:

• Topical drug instillation is preferred for ocular ailments due to convenience and noninvasiveness.
• Conventional eye drops exhibit poor drug bioavailability (<5%) because of physiological barriers like the cornea, tear turnover, and the blood-retinal barrier.
• These barriers impede drug penetration, especially to the posterior segment of the eye.

Purpose of the Study:

• To review the structural components of the eye and associated therapeutic challenges in drug delivery.
• To explore current developments in ocular therapeutic systems utilizing novel drug delivery platforms.
• To highlight strategies for enhancing drug holding time and permeation for improved ocular bioavailability.

Main Methods:

• Review of existing literature on ocular drug delivery systems.
• Analysis of physiological barriers affecting drug absorption in the eye.
• Discussion of nanotechnology-based platforms for ocular therapeutics.

Main Results:

• Nanotechnology platforms like nanomicelles, nanoparticles (NPs), nanosuspensions, liposomes, in situ gels, dendrimers, contact lenses, implants, and microneedles have been developed.
• These advanced systems are designed to overcome physiological barriers and improve drug delivery to ocular tissues.
• Controlled-drug-formulation strategies show potential for increasing drug concentration in specific ocular areas.

Conclusions:

• Novel drug delivery systems, particularly those based on nanotechnology, are crucial for overcoming ocular barriers.
• These advanced systems enhance drug bioavailability and therapeutic efficacy for treating eye diseases.
• Rational design of ocular therapeutics is key to improving drug concentration and treatment outcomes.