Ling W C
J Pharm Sci. 1978 Feb;67(2):218-23. doi: 10.1002/jps.2600670223.
The rheological parameters of rigidity and viscosity were studied for gelatin, both as a 6% solution and a 38% gel mass containing glycerin, sorbitol, and water. A compressive test for rigidity and a rotational shear method for viscosity were used to characterize the thermal degradation of several lots of alkali-processed calf-skin gelatin. The objective of this study was to use kinetic data for process predictions in the manufacturing of the gel mass for soft gelatin capsules. Empirical equations relating degradation to time, temperature and pH were derived for dilute gelatin solutions. Through parallel studies with a concentrated gel mass, other empirical equations were developed to predict degradation of the gel mass based on dilute solution data and processing conditions. Analysis of the kinetic data and empirical equations have generally confirmed earlier observations on degradation, except on quantitative aspects. While these equations are adequate for the intended use in process predictions, the study revealed substantial variability both within and among lots of commercial gelatin. These variabilities of uncertain causes contributed to inexact characterization of degradation, as demonstrated by the generally approximate results of process predictions.
对含有甘油、山梨醇和水的6%明胶溶液以及38%凝胶块的明胶的刚性和粘度流变学参数进行了研究。采用刚性压缩试验和粘度旋转剪切法对多批碱处理小牛皮明胶的热降解进行了表征。本研究的目的是利用动力学数据对软胶囊凝胶块的制造过程进行预测。推导了稀明胶溶液降解与时间、温度和pH值的经验方程。通过对浓缩凝胶块的平行研究，开发了其他经验方程，以根据稀溶液数据和加工条件预测凝胶块的降解。动力学数据和经验方程的分析总体上证实了早期关于降解的观察结果，但在定量方面除外。虽然这些方程足以用于过程预测的预期用途，但研究表明，商业明胶批次内部和批次之间存在很大的变异性。这些原因不明的变异性导致降解的表征不准确，过程预测的一般近似结果证明了这一点。
