Control of vitamin B₁₂ release from poly(ethylene glycol)/poly(butylene terephthalate) multiblock copolymers

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• 作者：van Dijkhuizen-Radersma ; R. ; Pé ; ters ; F.L.A.M.A. ; Stienstra ; N.A. ; Grijpma ; D.W. ; Feijen ; J. ; et. al.
• 关键词：Poly(ether ester) ; Controlled release ; Peptides ; Swelling ; Crystallinity
• 刊名：Biomaterials
• 出版年：2002
• 期刊代码：7_01429612
• 类别：ms
• 出版时间：March, 2002
• 卷：23
• 期：6
• 页码：1527-1536
• 文件大小：165 K

摘要

The release of vitamin B₁₂ (1355Da) from matrices based on multiblock copolymers was studied. The copolymers were composed of hydrophilic poly(ethylene glycol)-terephthalate (PEGT) blocks and hydrophobic poly(butylene terephthalate) (PBT) blocks. Vitamin B₁₂ loaded films were prepared by using a water-in-oil emulsion method. The copolymer properties, like permeability, could be varied by increasing the PEG-segment length from 300 up to 4000g/mol and by changing the wt%of PEGT. From permeation and release experiments, the diffusion coefficient of vitamin B₁₂ through PEGT/PBT films of different compositions was determined. The diffusion coefficient of vitamin B₁₂ was strongly dependent on the composition of the copolymers. Although an increased wt%of PEGT (at a constant PEG-segment length) resulted in a higher diffusion coefficient, a major effect was observed at increasing PEG-segment length. By varying the copolymer composition, a complete release of vitamin B₁₂ in 1 day up to a constant release for over 12 weeks was obtained. The release rate could be effectively tailored by blending copolymers with different PEG-segment lengths. The swelling and the crystallinity of the matrix could explain the effect of the matrix composition on the release behavior.