Study on a novel enzymatic colon-targeted particle of total saponins of Pulsatilla by mechanical grinding technology in a solvent free system

Oral colon-targeting preparation can achieve targeted drug release in the lesion site and have a great application prospect. In this study, we presented the principle of particle design in the field of materials science into the preparation of colon-targeting preparation. Enzymatic Pulsatilla saponins Colon-targeting composite Microparticles (EPCM) were prepared by mechanical grinding without any organic solvent. Firstly, Response Surface Methodology (RSM) designed by Box-Behnken was used to optimize the preparation process of EPCM, and the structure of EPCM was characterized. All-Atomic and Molecular Dynamics (AAMD) was used to calculate the compatibility between drugs and coating materials before and after release, so as to explain the principle of colon- targeted drug release in this method. Then, colon-targeting characteristics of EPCM in vitro and in vivo were investigated by experiments. Finally, the pharmacodynamics effects of this composite microparticles on Ulcerative Colitis (UC) induced by DSS in C57BL/6 mice were evaluated. The results demonstrated that the colon-targeting composite microparticles could be prepared by mechanical grinding based on particle design principle. The composite microparticles have appropriate colon-targeting drug release performance in vitro and in vivo, and have good anti-ulcerative colitis effect. This study provides a new idea for the preparation of oral colon-targeting preparation of Traditional Chinese medicine, and has evident reference value for the study of coating isolation and powder modification of traditional Chinese medicine for other purposes.