Knezevic Z, Gosak D, Hraste M, Jalsenjak I
Pliva Research Institute, Zagreb, Croatia.
J Microencapsul. 1998 Mar-Apr;15(2):237-52. doi: 10.3109/02652049809006853.
Ascorbic acid has been fluidized and microencapsulated with three different hydrophobic coating materials by the top-spray method. The experiments were conducted with polymethacrylate coating material formulated as a water dispersion, and ethyl-cellulose and waxy coating material both formulated as organic solutions. Characteristics of the fluidized bed procedure in conical geometry have been determined by estimation of two parameters: bed porosity and total pressure drop. A satisfactory agreement between experimental and calculated values has been reached. The following properties of the microencapsulated ascorbic acid have been determined: core content, bulk and tapped density, crystal size distribution prior and after microencapsulation, surface morphology and release profile. The comparison and evaluation of different hydrophobic coating materials have been performed on the basis of these findings.
已通过顶喷法将抗坏血酸与三种不同的疏水涂层材料进行流化和微囊化处理。实验使用了配制成水分散体的聚甲基丙烯酸酯涂层材料，以及均配制成有机溶液的乙基纤维素和蜡质涂层材料。通过估算两个参数（床层孔隙率和总压降）来确定锥形几何结构流化床工艺的特性。实验值与计算值之间已达成令人满意的一致性。已测定了微囊化抗坏血酸的以下性质：核心含量、堆积密度和振实密度、微囊化前后的晶体尺寸分布、表面形态和释放曲线。基于这些发现，对不同的疏水涂层材料进行了比较和评估。
