Drug-Loaded Nanoparticles Embedded in a Biomembrane Provide a Dual-Release Mechanism for Drug Delivery to the Eye.

PURPOSE: Topical delivery by eye drops, which accounts for ∼90% of all ophthalmic formulations, is inefficient for drug delivery to the posterior segment. Only 5% of the drug applied as drops reaches the target, whereas the rest is lost through tear drainage. A number of conditions such as glaucoma and proliferative retinopathy need sustained drug release to be therapeutically effective. The purpose of this study was to develop a novel dual-release drug delivery system to meet this requirement.

METHODS: Our system consists of lidocaine-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles suspended within a thin collagen membrane. This system provides constant contact with the cornea, and the nanoparticles supply a continuous release of medication, resulting in more drug reaching the target. This system provides dual release of the drug, from both the nanoparticles and the membrane.

RESULTS: The nanoparticles loaded into the membrane did not have a significant effect on light transmittance through the membrane compared with a commercial contact lens. The membranes containing nanoparticles showed a lesser burst release of 16.2% of the initial lidocaine loading than the free nanoparticles with a burst release of 41.8% of the initial lidocaine loading. The membrane containing nanoparticles showed a slow and continuous release of lidocaine of up to 23.4% of the initial loading after 7 days compared with 64% for the free nanoparticles.

CONCLUSIONS: The dual-release membrane system shows promise for a new drug delivery method to the eye with limited burst release and sustained delivery.