Department of Pharmaceutics and Biopharmaceutics, Christian Albrecht University Kiel, Gutenbergstr. 76, 24118 Kiel, Germany.
Int J Pharm. 2010 Mar 15;387(1-2):71-8. doi: 10.1016/j.ijpharm.2009.12.009. Epub 2010 Jan 15.
Modified lactoses are widely used as filler-binders in direct compression of tablets. Until today, little about the compaction behaviour of anhydrous alpha-lactose is known. In this study, a new method to prepare anhydrous alpha-lactose from alpha-lactose monohydrate by desiccation with heated ethanol was evaluated and the influence of amorphous content in the lactose powder prior to modification on powder properties, compaction behaviour and storage stability was determined. The modification process led to anhydrous alpha-lactose with decreased bulk and tapped density, increased flow rate and significantly higher specific surface area. Due to the higher specific surface area, the compaction behaviour of the anhydrous alpha-lactose was found to be significantly better than the compaction behaviour of powder blends consisting of alpha-lactose monohydrate and amorphous lactose. An influence of the amorphous content prior to modification could be observed only at higher compaction forces. In general, tablets of modified powders needed longer time to disintegrate directly after compression. However, the storage stability of modified tablets was found to be better compared to the amorphous-crystalline tablets which were influenced by storage conditions, initial crushing strength as well as amorphous content due to the re-crystallization of amorphous lactose during storage.
改性乳糖被广泛用作片剂直接压片的填充剂和粘合剂。直到今天，人们对无水α-乳糖的压缩行为知之甚少。在这项研究中，评估了一种用加热的乙醇干燥从α-乳糖一水合物制备无水α-乳糖的新方法，并确定了在改性前乳糖粉末中的无定形含量对粉末特性、压缩行为和储存稳定性的影响。改性过程导致无水α-乳糖的堆积密度和振实密度降低，流速增加，比表面积显著增加。由于比表面积较高，无水α-乳糖的压缩行为明显优于由α-乳糖一水合物和无定形乳糖组成的粉末混合物的压缩行为。仅在较高的压缩力下才能观察到改性前无定形含量的影响。一般来说，改性粉末压片在直接压片后需要更长的时间才能崩解。然而，与受储存条件、初始破碎强度以及由于储存过程中无定形乳糖再结晶而导致的无定形含量影响的无定形-结晶片剂相比，改性片剂的储存稳定性更好。
