Intraocular administration of biodegradable microspheres to increase drug bioavailability and extend therapeutic effect

Abstract

AbstractPurpose Treatment of posterior segment diseases often requires repeated intravitreal injections to achieve and maintain steady state concentrations of the active substance in the target site. However, intraocular injections are associated to adverse effects and the risk of complications increases with the number of administrations. Biodegradable microspheres (MPs) are considered an alternative to multiple injections as they are able to release the encapsulated drug over weeks or months. Copolymers of lactic and glycolic acids (PLGA) are FDA approved biodegradable biomaterials commonly used to prepare MPs. They are biocompatible and degrade to metabolic products that are easily eliminated from the body. The main advantages of these systems is that they can be injected as a conventional suspension without surgical procedures. After intravitreal administration, PLGA microspheres suffer aggregation disappearing from the site of injection after delivering the drug. Microspheres can be loaded with different active substances (small molecules and biotechnological products) useful to treat vitreoretinal diseases. Administration of microparticles can be performed by periocular, intravitreal, sub‐ retinal, or other intraocular routes to treat posterior segment disorders.Conclusion PLGA microspheres are emerging therapeutic tools for the treatment of posterior segment diseases in which steady state concentrations of the active substance is needed over an extended period of time. Acknowledgements: PANOPTES‐Peptide‐based Nanoparticles as Ocular Drug Delivery Vehicles‐ collaborative project (FP7‐NMP‐2009); Spanish Ministry of Economy MAT 2010‐18242, UCM Research Group 920415 and RETICs (RD07/0062/2002)