Elkheshen S, Zia H, Needham T E, Badawy A, Luzzi L A
Department of Pharmaceutics, University of Rhode Island, Kingston.
J Microencapsul. 1992 Jan-Mar;9(1):41-51. doi: 10.3109/02652049209021221.
A potential haemoperfusion system has been developed using activated charcoal encapsulated with a polyacrylate-polymethacrylate copolymer. The film forms a coating of great mechanical strength around the charcoal particles, which is readily permeable to water and certain dissolved substances. The charcoal granules were coated with various membrane thicknesses consisting of a 2-10 per cent (by weight) film coat, using the modified method of non-solvent addition of Benita et al. (1985). The effect of various encapsulation variables such as stirring rate, rate of addition of non-solvent, percentage of coating polymer and concentration of a non-wall-forming polymer (PIB) in the non-solvent phase on adsorptivity, as well as the release of fine particles, were determined. The effect of coating thickness on the adsorption rate of the coated charcoal was investigated by constructing Higuchi diffusion model plots using methylene blue as a model adsorbate. It was found that the membrane permeability can be adjusted by changing experimental conditions to obtain high adsorption capacity along with a low level of released particles. Further, the effect of presoaking of the coated charcoal in purified water, normal saline, and 0.067 M phosphate buffer pH 7.4 (for 24 h at 37 degrees C) on the rate of adsorption of methylene blue was also evaluated.
一种潜在的血液灌流系统已被开发出来，该系统使用包裹有聚丙烯酸酯 - 聚甲基丙烯酸酯共聚物的活性炭。该薄膜在炭颗粒周围形成具有很大机械强度的涂层，该涂层对水和某些溶解物质具有良好的渗透性。采用贝尼塔等人（1985年）改进的非溶剂添加法，用由2 - 10%（重量）薄膜涂层组成的不同膜厚度包裹炭颗粒。测定了各种包封变量，如搅拌速率、非溶剂添加速率、涂层聚合物百分比以及非溶剂相中非成膜聚合物（PIB）浓度对吸附性的影响，以及细颗粒的释放情况。通过以亚甲基蓝作为模型吸附质构建Higuchi扩散模型图，研究了涂层厚度对包覆炭吸附速率的影响。结果发现，通过改变实验条件可以调节膜的渗透性，从而在释放颗粒水平较低的情况下获得高吸附容量。此外，还评估了将包覆炭在纯净水、生理盐水和pH 7.4的0.067 M磷酸盐缓冲液中（在37℃下浸泡24小时）预浸泡对亚甲基蓝吸附速率的影响。
