Material manufacturability classification in high shear wet granulation process of Chinese medicine

Abstract

The high shear wet granulation(HSWG) process of Chinese medicine has a complicated mechanism. There are many influencing factors that contribute to this process. In order to summarize the manufacturability of different kinds of materials in HSWG, this paper constructed a material library composed of 11 materials, including 4 Chinese medicine extracts and 7 pharmaceutical excipients. Each material was described by 22 physical parameters. Several binders were employed, and their density, viscosity and surface tension were characterized. Combining empirical constraints and the principle of randomization, 21 designed experiments and 8 verification experiments were arranged. The partial least squares(PLS) algorithm was used to establish a process model in prediction of the median granule size based on properties of raw materials and binders, and process parameters. The surface tension and density of binders, as well as the maximum pore saturation were identified as key variables. In the latent variable space of the HSWG process model, all materials could be divided into three categories, namely the Chinese medicine extracts, the diluents and the disintegrants. The granulation of Chinese medicine extracts required low viscosity and low amount of binder, and the resulted granule sizes were small. The diluent powders occupied a large physical space, and could be made into granules with different granule sizes by adjusting the properties of binders. The disintegrants tended to be made into large granules under the condition of aqueous binder. The combination use of material database and multivariate modeling method is conducive to innovate the knowledge discovery of the wet granulation process of Chinese medicine, and provides a basis for the formulation and process design based on material attributes.