Studies on Tabletine; Properties of Lactose; The Effect of Initial Particle Size on Binding Properties and Dehydration Characteristics of α-Lactose Monohydrate

Abstract

Unmilled particle size fractions of α-lactose monohydrate were used to study its dehydration and tableting characteristics. It appleared that the speed of dehydration of the substance was dependent on both the powder surface area and the temperature.

The results made it possible to explain changes in thermograms which are observed after milling or compacting the material, by pointing to the surface enlargement due to these mechanical treatments.

Tablet pore surface areas were derived from mercury porosimetry measurements. By plotting tablet strength against tablet pore surface area a linear relationship was obtained for different sieve fractions. This was concluded to point to a similar proportionality between tablet pore surface area and binding surface area for the fractions used. It was observed that only fractions which intensively fragment fitted this line. From this it was suggested that in general the tablet strength of compacts of α-lactose monohydrate is mainly determined by fragmentation. For small particles counts however, that other mechanisms of consolidation play a predominant role so that the proportionality between tablet pore surface area and binding surface area gets another value.