Eriksson M, Alderborn G
Astra Läkemedel AB, Södertälje, Sweden.
Pharm Res. 1995 Jul;12(7):1031-9. doi: 10.1023/a:1016214616042.
The compression behaviour and the compactability of particles have been studied. In addition, an expression describing the bond strength over a tablet cross section was derived and these calculated values were compared with the experimentally determined tablet tensile strength values.
The compression behaviour of particles of a series of size fractions of four materials were assessed by tablet surface areas (particle fragmentation propensity) and by yield pressures (particle deformability), derived from in die Heckel profiles. The porosity and the tensile strength of the tablets were also determined.
Sodium chloride and sodium bicarbonate possessed limited fragmentation while the converse applied for sucrose and lactose. Sodium chloride and sodium bicarbonate were the extreme materials with respect to particle deformability and compactability. Except for sodium chloride, a limited effect of original particle size on the compactability of the particles was observed.
The observations on the compactability of the powders was explained by postulating that fragmentation affects mainly the number of bonds in a compact cross section, while deformation affects mainly the bonding force of these bonds, through a relationship with the contact area between a pair of particles. The deviations between the predicted strength of particle-particle bonds and the determined tensile strength values was explained by a high bonding capacity of some particles, e.g. due to an unpredicted high surface deformability, or by a fracture mechanic effect during tablet strength determination.
研究了颗粒的压缩行为和可压性。此外，推导了描述片剂横截面结合强度的表达式，并将这些计算值与实验测定的片剂抗张强度值进行了比较。
通过片剂表面积（颗粒破碎倾向）和由模内赫克尔曲线得出的屈服压力（颗粒可变形性），评估了四种材料一系列粒径级分颗粒的压缩行为。还测定了片剂的孔隙率和抗张强度。
氯化钠和碳酸氢钠的颗粒破碎有限，而蔗糖和乳糖则相反。氯化钠和碳酸氢钠在颗粒可变形性和可压性方面是极端材料。除氯化钠外，观察到原始粒径对颗粒可压性的影响有限。
通过假设破碎主要影响压片横截面中的键数量，而变形主要通过与一对颗粒之间的接触面积的关系影响这些键的结合力，来解释对粉末可压性的观察结果。颗粒间键的预测强度与测定的抗张强度值之间的偏差，是由于某些颗粒的高结合能力，例如由于不可预测的高表面可变形性，或由于片剂强度测定期间的断裂力学效应。
