화학공학소재연구정보센터
Powder Technology, Vol.114, No.1-3, 118-124, 2001
Development of spherical crystal agglomerates of an aspartic acid salt for direct tablet making
Agglomerates of an aspartic acid salt were developed by means of a non-typical spherical crystallization technique. The aspartic acid salt was crystallized by a salting-out method combined with cooling. Traditional mechanical stirring crystallization (samples A and B) and the recirculation process (sample C) were used. The control material was commercial aspartic acid salt with very poor flowability and compressibility. The particle sizes of the samples were measured by sieve analysis. The morphology of the crystals and crystal agglomerates was controlled by SEM. The specific surfaces of the products were determined by the BET method and the micropore volumes were calculated via the BJH theory. The Carr index, rearrangement constant, plasticity and compressibility values were calculated. The samples were controlled by thermoanalytical investigations (TG, DTG and DSC). Both of the crystallization techniques used resulted in spherical agglomerates of the aspartic acid salt with very good flowability and compressibility parameters. Primarily sample B, with a closed "cauliflower-like" structure, can be suggested for tablet making involving a large mass (e.g., chewable tablets) by direct tablet pressing. Faster initial cooling rate and slower stirring rate were very favourable in the building-up of crystal agglomerates of sample B with a closed structure and a large particles. Sample B can be suggested further for capsule filling because of its high poured density, very good flowability and fast rearrangement.