Study on Low Viscosity Hydroxypropyl Methylcellulose Obtained by Electron Beam Irradiation and Its Role in Powder Modification

Abstract In this study, hydroxypropyl Methylcellulose (HPMC) with lower viscosity was obtained by electron beam irradiation (EBI), and its physical modifiers for pharmaceutical powders was investigated when it was used during spray drying. After HPMC was irradiated at a dose of 150 kGy, the main structure of HPMC was not affected, and the substitution degree of methoxy and hydroxypropyl was not destroyed significantly. As the irradiation dose increased from 10 to 150 kGy, the molecular weight and viscosity of HPMC decreased continuously. The results of spray drying showed that HPMC could quickly migrate to the surface of the liquid medicine to cover droplets during spray drying and atomization, which improved the hygroscopicity and increased the softening point of spray-dried powder. And the powder water content is lower. After the powder is prepared into particles, the dissolution rate of particles is faster. Therefore, the modified powder exhibits better physical properties. The low viscosity HPMC obtained by electron beam irradiation is suitable for powder modification materials during spray drying, and is expected to be developed as excipient in traditional Chinese medicine and other industries.