title: Combined application of extrusion-spheronization and hot-melt coating technologies for improving moisture-proofing of herbal extracts.
abstract: The aim of this research was to investigate the moisture-proofing effect and its mechanism for herbal extracts using extrusion-spheronization combined with hot-melt coating. Guizhi Fuling (GF) compound herbal extract with high hygroscopicity was used as a model drug. In the process of extrusion-spheronization, pellets containing 100% GF were prepared, and then coated with hot-melt coating material using a traditional coating pan. The moisture sorption data for GF were determined by storage at a series of different relative humidities. When the pellets were coated with a 96:4 mixture of stearic acid and polyethylene glycol 6000, the cumulative drug release was over 90% at 45 min while the moisture content was 4.9% at 75% RH within 10 days. These pellets have better moisture-proofing than those coated with Opadry AMB at the same coating level due to a different moisture sorption mechanism. The moisture sorption behavior of the hot-melt coating can be attributed to water vapor diffusion via a porous matrix system, while the Opadry AMB coating system involved a swelling controlled system. The Higuchi model was the best fit for the moisture sorption of the hot-melt coating in all formulations whereas the Opadry AMB coating fitted the Nuttanan model.
authors.affiliation: College of Pharmacy, Shenyang Pharmaceutical University, Wenhua Road, No. 103, Shenyang 110016, PR China.
authors.forename: Hao
authors.initials: H
authors.lastname: Chen
authors.forename: Shuai
authors.initials: S
authors.lastname: Shi
authors.forename: Aina
authors.initials: A
authors.lastname: Liu
authors.forename: Xing
authors.initials: X
authors.lastname: Tang
mesh_terms: D000327:Adsorption; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003692:Delayed-Action Preparations; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D006358:Hot Temperature; D057927:Hydrophobic and Hydrophilic Interactions; D008855:Microscopy, Electron, Scanning; D012995:Solubility; D013499:Surface Properties; D013678:Technology, Pharmaceutical / Q000379:methods*; D044366:Transition Temperature; D014783:Viscosity; D014867:Water / Q000032:analysis*
chemical_list: D020099:Coated Materials, Biocompatible; D003692:Delayed-Action Preparations; D004365:Drugs, Chinese Herbal; D014867:Water