Grijseels H, Harden B T, De Blaey C J
Pharm Weekbl Sci. 1983 Jun 24;5(3):88-94. doi: 10.1007/BF01960983.
The dissolution rate of a nicotinic acid tablet surface was measured in a dissolution system where mass transport in the solvent is governed by a combination of natural and forced convection. While such experimental conditions were chosen that natural convection outweighted forced convection, the dissolution rate increasing effect of large pores in the tablet surface was studied. To that end cylindrical pores were drilled into the tablet. The increase in dissolution rate was measured as a function of the number of pores, their depth and diameter and their position with respect to each other and to the centre of the dissolving surface. The results are discussed with regard to the hydrodynamic conditions near the pores. In addition to the regularly arranged cylindrical pores a more irregular configuration of cubic pores was investigated. These pores were created by embedding cubic sodium chloride crystals in the tablet surface during the compression procedure. After the sodium chloride particles had dissolved rapidly a porous surface of much slower dissolving nicotinic acid remained. The dissolution rate of the porous surface was determined and a comparison was made between surfaces with and without pores of several sizes.
在一个溶剂中的传质由自然对流和强制对流共同控制的溶出系统中，对烟酸片表面的溶出速率进行了测定。虽然选择的实验条件是自然对流超过强制对流，但研究了片剂表面大孔隙对溶出速率的增加作用。为此，在片剂上钻了圆柱形孔。测定了溶出速率的增加与孔的数量、深度、直径以及它们彼此之间和相对于溶解表面中心的位置的函数关系。根据孔附近的流体动力学条件对结果进行了讨论。除了规则排列的圆柱形孔外，还研究了立方孔这种更不规则的结构。这些孔是在压制过程中将立方氯化钠晶体嵌入片剂表面而形成的。氯化钠颗粒迅速溶解后，留下了溶解速度慢得多的烟酸多孔表面。测定了多孔表面的溶出速率，并对有不同尺寸孔和无孔的表面进行了比较。
