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Abstract #10511 Published in IGR 6-1
Controlled release of ethacrynic acid from poly(lactide-co-glycolide) films for glaucoma treatment
Wang Y; Challa P; Epstein DL; Yuan FBiomaterials 2004; 25: 4279-4285
Ethacrynic acid (ECA) is a potential glaucoma drug that can reduce intraocular pressure (IOP). However, conventional methods of ECA administration may cause toxicity to normal eye tissues and are inconvenient to patients. Therefore, the authors developed and characterized an ECA loaded poly(lactide-co- glycolide) (PLGA) copolymer film, and quantified the therapeutic efficacy of the film implanted in the rabbit eye. In the aqueous medium, the release of ECA from the PLGA50:50 film was time dependent and more than 90% of ECA was released within a week. This release profile was consistent with the kinetics of water uptake and microstructural changes of PLGA50:50 films as revealed by an electron microscopy examination. ECA release and PLGA degradation caused a gradual pH decrease in the release medium. The total pH decrease was 0.4 unit in three days. The authors also observed that the initial rate of ECA release was positively correlated with the weight ratio of ECA versus PLGA and inversely correlated with the molar ratio of lactide versus glycolide in PLGA films. At the end of a three-day incubation period, the cumulative release of ECA from PLGA50:50, PLGA85:15 and PLGA100:00 films were 78.8, 9.35 and 3.60%, respectively. When the PLGA50:50 film loaded with ECA was implanted into the sclera of rabbit eyes, IOP was significantly reduced and the reduction was maintained for at least ten days. These data indicate that PLGA films have a potential to be used as a controlled ECA release device for glaucoma treatment.
Dr. F. Yuan, Department of Biomedical Engineering, 136 Hudson Hall, Duke University, Durham, NC 27708, USA
Classification:
11.14 Investigational drugs; pharmacological experiments (Part of: 11 Medical treatment)
11.16 Vehicles, delivery systems, pharmacokinetics, formulation (Part of: 11 Medical treatment)