Etoposide-Loaded Poly(Lactic-co-Glycolic Acid) Intravitreal Implants: <italic>In Vitro</italic> and <italic>In Vivo</italic> Evaluation.

Etoposide-loaded poly(lactic-co-glycolic acid) implants were developed for intravitreal application. Implants were prepared by a solvent-casting method and characterized in terms of content uniformity, morphology, drug-polymer interaction, stability, and sterility. <italic>In vitro</italic> drug release was investigated and the implant degradation was monitored by the percent of mass loss. Implants were inserted into the vitreous cavity of rabbits’ eye and the <italic>in vivo</italic> etoposide release profile was determined. Clinical examination and the Hen Egg Test-Chorioallantoic Membrane (HET-CAM) method were performed to evaluate the implant tolerance. The original chemical structure of the etoposide was preserved after incorporation in the polymeric matrix, which the drug was dispersed uniformly. <italic>In vitro</italic>, implants promoted sustained release of the drug and approximately 57% of the etoposide was released in 50 days. <italic>In vivo</italic>, devices released approximately 63% of the loaded drug in 42 days. Ophthalmic examination and HET-CAM assay revealed no evidence of toxic effects of implants. These results tend to show that etoposide-loaded implants could be potentially useful as an intraocular etoposide delivery system in the future. [ABSTRACT FROM AUTHOR]