Abstract
Microspheres containing Norgestrel (MCN) were prepared from block copolymer of ε-caprolactone and dl-lactide (PCL-b-PLA) through solvent-evaporation process. The MCN produced at 10°C using soluble or wettable solvent bears fine and close surface which endows it a higher ability to control drug release. The block copolymer showed a double release mechanism—diffusion release contributed by PCL segment and erosion-caused release by PLA segment. The effects of these two pathways can be balanced by tailoring the ratio of CL/LA in PCL-b-PLA to such an extent that the erosion-caused release could just compensate the declined amount resulted from diffusion release and a whole zero-order kinetics can be actually achieved. Such a balance has been accomplished when the ratio of 60/40 is used which proved to be a promising controlled delivery system.
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Song, C., Sun, H. & Feng, X. Microspheres of Biodegradable Block Copolymer for Long-Acting Controlled Delivery of Contraceptives. Polym J 19, 485–491 (1987). https://doi.org/10.1295/polymj.19.485
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DOI: https://doi.org/10.1295/polymj.19.485
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