a Faculty of Chemical Technology , Institute of Environmental and Chemical Engineering, University of Pardubice , Pardubice , Czech Republic.
b Department of Pharmaceutical Technology, Faculty of Pharmacy in Hradec Kralove , Charles University , Prague , Czech Republic.
Pharm Dev Technol. 2019 Jan;24(1):80-88. doi: 10.1080/10837450.2018.1425432. Epub 2018 Jan 22.
Rheological behaviour of pharmaceutical semisolid preparations significantly affects manufacturing process, administration, stability, homogeneity of incorporated drug, accuracy of dosing, adhesion in the place of application, drug release, and resulting therapeutic effect of the product. We performed test of consistency by penetrometry, rotational, oscillation and creep tests, and squeeze and tack tests of model samples to introduce methods suitable for characterization and comparison of semisolids in practice. Penetrometry is a simple method allowing sorting the semisolids to low and high stress-resistant materials but deficient for rheological characterization of semisolids. Value of yield stress, generally considered to be appropriate feature of semisolids, is significantly influenced by the method of testing and the way of evaluation. The hysteresis loops of model semisolids revealed incomplete thixotropy, therefore, three-step thixotropy test was employed. Semisolids showed nonlinear response in the creep phase of tests and partial recovery of structure by storing energy in the recovery phase. Squeeze and tack tests seem to be convenient ways for comparison of semisolids. Our study can contribute to a better understanding of different flow behaviour of semisolids given by different physicochemical properties of excipients and can bring useful approaches to evaluation and comparison of semisolids in practice.
药物半固体制剂的流变行为对其生产过程、给药方式、稳定性、药物均匀性、给药准确性、应用部位的附着性、药物释放以及产品的治疗效果都有显著影响。我们通过穿刺试验、旋转、振荡和蠕变试验以及模型样品的挤压和粘性试验来测试稠度，以介绍适合于半固体制剂实际特性化和比较的方法。穿刺试验是一种简单的方法，可以对半固体制剂进行低和高抗应力材料的分类，但对于半固体制剂的流变特性描述不足。屈服应力值通常被认为是半固体制剂的适当特征，但它受到测试方法和评估方式的显著影响。模型半固体制剂的滞后回线显示出不完全的触变性，因此采用了三步触变性测试。半固体制剂在测试的蠕变阶段表现出非线性响应，并通过在恢复阶段存储能量来部分恢复结构。挤压和粘性试验似乎是比较半固体制剂的方便方法。我们的研究有助于更好地理解不同物理化学性质的辅料对半固体制剂的不同流动行为，并为半固体制剂的评估和比较提供有用的方法。
