Controlled and continuous release ocular drug delivery systems: pros and cons

Area of Science:

• Ophthalmology
• Pharmaceutics
• Drug Delivery Systems

Background:

• Topical ocular drug administration is preferred for eye surface and anterior segment diseases due to rapid action and patient acceptance.
• Conventional ophthalmic dosage forms (e.g., eye drops) exhibit poor ocular bioavailability, typically less than 5%, owing to the eye's unique anatomical and physiological barriers.
• Significant drug loss occurs via nasolacrimal drainage and non-productive absorption, limiting therapeutic effectiveness.

Purpose of the Study:

• To critically appraise various drug delivery strategies designed for controlled and continuous drug release to the ocular surface.
• To evaluate the advantages and drawbacks of different approaches for enhancing ocular drug bioavailability.
• To review research advancements in ocular drug delivery over the past three decades.

Main Methods:

• Literature review and critical appraisal of scientific publications.
• Analysis of pharmaceutical approaches for sustained ocular drug delivery.
• Examination of research data on drug delivery systems for ocular surface application.

Main Results:

• Controlled ocular drug delivery systems offer a promising approach to overcome the limitations of conventional eye drops.
• Various strategies exist to achieve sustained drug release, compensating for drug loss and improving bioavailability.
• The review synthesizes findings on the efficacy and challenges associated with different controlled ocular drug delivery methods.

Conclusions:

• Controlled and continuous drug release is crucial for improving the therapeutic outcomes of topical ocular treatments.
• Advanced drug delivery systems are essential to enhance ocular bioavailability and overcome physiological barriers.
• Further research into innovative ocular drug delivery strategies is warranted to optimize treatment for eye conditions.