Division of Pharmaceutical Technology, Faculty of Pharmacy, University of Helsinki, 00014 University of Helsinki, Finland.
Int J Pharm. 2013 Apr 15;447(1-2):218-23. doi: 10.1016/j.ijpharm.2013.03.007. Epub 2013 Mar 15.
Changes in the solid-state form can occur during dissolution testing of drugs. This can often complicate interpretation of results. Additionally, there can be several mechanisms through which such a change proceeds, e.g. solvent-mediated transformation or crystal growth within the drug material itself. Here, a mathematical model was constructed to study the dissolution testing of a material, which undergoes such changes. The model consisted of two processes: the recrystallization of the drug from a supersaturated liquid state caused by the dissolution of the more soluble solid form and the crystal growth of the stable solid form at the surface of the drug formulation. Comparison to experimental data on theophylline dissolution showed that the results obtained with the model matched real solid-state changes and that it was able to distinguish between cases where the transformation was controlled either by solvent-mediated crystallization or solid-state crystal growth.
在药物的溶解测试过程中，固体形态可能会发生变化。这通常会使结果的解释变得复杂。此外，可能存在几种使这种变化发生的机制，例如溶剂介导的转变或药物本身的晶体生长。在这里，构建了一个数学模型来研究经历这种变化的材料的溶解测试。该模型由两个过程组成：由于更易溶的固体形态的溶解而导致的过饱和液体状态下药物的再结晶，以及药物制剂表面稳定固体形态的晶体生长。与茶碱溶解的实验数据进行比较表明，模型得到的结果与实际的固体状态变化相符，并且能够区分溶剂介导的结晶或固态晶体生长控制的情况。
