An update on the latest strategies in retinal drug delivery

ABSTRACT

Introduction

Retinal drug delivery has witnessed significant advancements in recent years, mainly driven by the prevalence of retinal diseases and the need for more efficient and patient-friendly treatment strategies.

Areas covered

Advancements in nanotechnology have introduced novel drug delivery platforms to improve bioavailability and provide controlled/targeted delivery to specific retinal layers. This review highlights various treatment options for retinal diseases. Additionally, diverse strategies aimed at enhancing delivery of small molecules and antibodies to the posterior segment such as implants, polymeric nanoparticles, liposomes, niosomes, microneedles, iontophoresis and mixed micelles were emphasized. A comprehensive overview of the special technologies currently under clinical trials or already in the clinic was provided.

Expert opinion

Ideally, drug delivery system for treating retinal diseases should be less invasive in nature and exhibit sustained release up to several months. Though topical administration in the form of eye drops offers better patient compliance, its clinical utility is limited by nature of the drug. There is a wide range of delivery platforms available, however, it is not easy to modify any single platform to accommodate all types of drugs. Coordinated efforts between ophthalmologists and drug delivery scientists are necessary while developing therapeutic compounds, right from their inception.

KEYWORDS:

• Retinal drug delivery
• implants
• polymeric nanocarriers
• liposomes
• niosomes
• microneedles
• mixed micelles

Article highlights

• Administering drugs to the posterior segment of the eye pose significant challenges, primarily due to anatomical and physiological barriers

• Topical application and systemic administration of drugs results in limited drug bioavailability in the back of the eye.

• Intravitreal injections provides high concentration in the target tissues such as retina, however, frequent intravitreal injections increase the risk of complications and treatment cost.

• Minimally invasive periocular routes such as peribulbar, retrobulbar, sub-tenon, sub-conjunctival route have gained prominence.

• Novel drug delivery approaches using implants, polymeric nanoparticles, liposomes, niosomes, microneedles, iontophoresis and mixed micelles have gained increasing importance in treating retinal diseases as they provide sustained drug release and offer minimally invasive delivery.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Additional information

Funding

This paper was not funded.