title: Preparation and evaluation of sustained-release solid dispersions co-loading gastrodin with borneol as an oral brain-targeting enhancer.
abstract: Borneol is a traditional Chinese medicine that can promote drug absorption from the gastrointestinal tract and distribution to the brain. However, stomach irritation may occur when high doses of borneol are used. In the present work, gastrodin, the main bioactive ingredient of the traditional Chinese drug "Tianma" (Rhizoma Gastrodiae) was used as a model drug to explore reasonable application of borneol. Sustained-release solid dispersions (SRSDs) for co-loading gastrodin and borneol were prepared using ethylcellulose as a sustained release matrix and hydroxy-propyl methylcellulose as a retarder. The dispersion state of drug within the SRSDs was analyzed by using scanning electron microscopy, differential scanning calorimetry, and powder X-ray diffractometry. The results indicated that both gastrodin and borneol were molecularly dispersed in an amorphous form. Assay of in vitro drug release demonstrated that the dissolution profiles of gastrodin and borneol from the SRSDs both fitted the Higuchi model. Subsequently, gastric mucosa irritation and the brain targeting of the SRSDs were evaluated. Compared with the free mixture of gastrodin and borneol, brain targeting of SRSDs was slightly weaker (brain targeting index: 1.83 vs. 2.09), but stomach irritation obviously reduced. Sustained-release technology can be used to reduce stomach irritation caused by borneol while preserving sufficient transport capacity for oral brain-targeting drug delivery.
authors.affiliation: School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Cai
authors.affiliation: School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China.
authors.forename: Xiaolu
authors.initials: X
authors.lastname: Lei
authors.affiliation: School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China.
authors.forename: Zhufen
authors.initials: Z
authors.lastname: Lin
authors.affiliation: School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhao
authors.affiliation: School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China.
authors.forename: Feizhen
authors.initials: F
authors.lastname: Wu
authors.affiliation: Institute of Pharmaceutical Research, Kunming Pharmaceutical Co., Kunming 650100, China.
authors.forename: Zhaoxiang
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Institute of Pharmaceutical Research, Kunming Pharmaceutical Co., Kunming 650100, China.
authors.forename: Junxue
authors.initials: J
authors.lastname: Pu
authors.affiliation: School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China ; International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
authors.forename: Zhongqiu
authors.initials: Z
authors.lastname: Liu
keywords: Borneol; Brain-targeting; Gastric mucosa irritation; Gastrodin; Oral drug delivery; Sustained-release