Transscleral Delivery of Dexamethasone-Loaded Microparticles Using a Dissolving Microneedle Array

Area of Science:

• Ophthalmology
• Biomaterials Science
• Drug Delivery Systems

Background:

• Ocular drug delivery faces challenges due to biological barriers.
• Microneedles (MNs) offer a promising approach for overcoming these barriers.
• Dexamethasone (Dex) is a corticosteroid used for various ocular conditions.

Purpose of the Study:

• To develop and evaluate a novel dissolvable microneedle array for ocular drug delivery.
• To achieve controlled transscleral delivery of dexamethasone using PLGA microparticles.
• To assess the efficacy and safety of the microneedle system for posterior eye drug deposition.

Main Methods:

• Formulation of dissolvable microneedles loaded with dexamethasone-PLGA microparticles.
• Mechanical testing of microneedles for scleral penetration capability (porcine model).
• Quantification of dexamethasone permeation through the sclera and distribution within the ocular globe.

Main Results:

• Microneedles demonstrated sufficient strength for porcine scleral penetration.
• Dexamethasone permeation was significantly higher compared to topical delivery.
• 19.2% of administered dexamethasone reached the vitreous humour, with microparticle diffusion confirmed in the sclera.

Conclusions:

• The developed microneedle system enables minimally invasive, controlled dexamethasone delivery to the posterior eye.
• This approach offers improved drug bioavailability and patient convenience through self-administration.
• Dissolvable microneedles represent a viable strategy for enhancing ocular drug delivery efficacy.