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Advisor(s)
Abstract(s)
Implantable dorzolamide-loaded discs were prepared by blending poly(ε-caprolactone), PCL, with poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide), Lu. By blending, crystallinity, water uptake and mass loss were modified relative to the pure polymers. Burst was diminished by coating the discs with a PCL shell. All samples presented burst release except PCL-coated samples that showed controlled release during 18 days. For PCL-coated samples, barrier control of diffusion coupled with partition control from the core slowed down the release, while for 50/50 Lu/PCL-coated samples, the enhancement in the porosity of the core diminished partition control of drug release. Nonlinear regression analysis suggested that a degradation model fully describes the release curve considering a triphasic release mechanism: the instantaneous diffusion (burst), diffusion and polymer degradation stages. The MTT test indicated that the materials are not cytotoxic for corneal endothelial cells. A good in vitro–in vivo correlation was obtained, with similar amounts of drug released in vitro and in vivo. The discs decreased intraocular pressure (IOP) in normotensive rabbit eyes by 13.0% during 10 days for PCL-coated and by 13.0% during 4 days for 50/50 Lu/PCL-coated samples. The percentages of IOP decrease are similar to those obtained by dorzolamide eyedrop instillation (11.0%).
Description
Keywords
PCL Anti-glaucoma Sustained release
Citation
Natu, M.V., Gaspar, M.N., Ribeiro, C.A., Correia, I.J., Silva, D., de Sousa, H.C. e Gil, M.H. (2011) “A poly(ε-caprolactone) device for sustained release of an anti-glaucoma drug”, Biomedical Materials, Vol. 6(2): 025003
Publisher
IOPSCIENCE