Lemmouchi Y, Schacht E, Lootens C
Polymer Materials Research Group, Institute for Biomedical Technologies, IBITECH, University of Gent, Krijgslaan 281, B-9000 Ghent, Belgium.
J Control Release. 1998 Oct 30;55(1):79-85. doi: 10.1016/s0168-3659(98)00021-2.
In this study, commercial available poly(epsilon-caprolactone)s and poly(d,l-lactide)s of different molecular masses were used. Slow release devices (SRD) were obtained as rods of suitable diameters by extrusion of polymer-drug mixtures (75:25, w/w) which were prepared by the solution casting method. The rods were coated by dipping them in a methylene chloride solution of the core polymer. The in vitro release of the selected drugs, isometamidium chloride (IMM) and ethidium bromide (EtBr) from such rods was carried out in phosphate buffer (PB) pH 7.4 at 37 degreesC. The release data show that the release of IMM is faster than for EtBr. During the first stage, the release of IMM is governed by osmotic pressure whereas the release of EtBr is mainly diffusion controlled. The in vitro release of these drugs is governed by polymer matrix degradation at the later stage of the release process. The in vitro release could be controlled by drug loading, polymer molecular mass, polymer mixtures, coating thickness and device geometry.
在本研究中，使用了市售的不同分子量的聚（ε-己内酯）和聚（d，l-丙交酯）。通过溶液浇铸法制备聚合物-药物混合物（75:25，w/w），然后将其挤出成合适直径的棒材，从而获得缓释装置（SRD）。将棒材浸入核心聚合物的二氯甲烷溶液中进行包衣。在37℃、pH 7.4的磷酸盐缓冲液（PB）中对这些棒材中所选药物氯异甲噻酮（IMM）和溴化乙锭（EtBr）进行体外释放实验。释放数据表明，IMM的释放速度比EtBr快。在第一阶段，IMM的释放受渗透压控制，而EtBr的释放主要受扩散控制。在释放过程的后期，这些药物的体外释放受聚合物基质降解的影响。体外释放可通过药物负载量、聚合物分子量、聚合物混合物、包衣厚度和装置几何形状来控制。
