Preparation and Evaluation of Andrographolide Solid Dispersion Vectored by Silicon Dioxide.
BACKGROUND
Andrographolide (Andro) is a "natural antibiotic" as well as a typical insoluble drug. The purpose of this study was to investigate the feasibility of commercially available silica (SiO2) as a carrier of solid dispersion to enhance the dissolution of Andro.


METHODS
The solvent evaporation method was adopted, and a series of process parameters were studied to prepare a solid dispersion. Andro, SiO2, physical mixture, and solid dispersion were characterized with respect to particle size distribution, special surface area, pore volume, and scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction studies.


RESULTS
Single factor test suggested the best preparation of solid dispersion was the drug and carrier (SiO2B) ratio of 1:8, with tetrahydrofuran as the solvent, and a recovery temperature of 50°C. Compared to crude drug and mixture, solid dispersion was found to form a unique structure to disperse the drug and displayed superior performance in rapid dissolution.


CONCLUSIONS
The present study signifies the commercially available SiO2 is an excellent but cheap carrier to improve the dissolution of Andro. Our results provide a highly operability approach for improving the dissolution of insoluble natural products and are beneficial for the clinical effects improvement.


CONCLUSIONS
The potential of commercially available silica as a carrier for enhancing the insoluble drug dissolution was investigatedFactors affecting the dissolution of solid dispersion were investigatedSolid dispersion formed a unique structure to disperse the drug and release drug rapidlyCommercially available silica is an excellent but cheap carrier to improve the dissolution of Andro. Abbreviation used: Andro: Andrographolide, BCS: Biopharmaceutics Classification System, SDS: Tetrahydrofuran and Sodium dodecyl sulfate, HPLC: High Performance Liquid Chromatography, SEM: Scanning Electron Microscope, BET: Brumauer-Emmett-Teller, FTIR: Fourier Transform Infrared Spectroscopy, XRD: X-ray Diffraction.
Department of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China.
Dingkun
D
Zhang
Teaching Hospital of Chengdu University of TCM, Chengdu 610072, China.
Junzhi
J
Lin
Department of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China.
Fang
F
Zhang
Department of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China.
Xue
X
Han
Department of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China.
Li
L
Han
Key Laboratory of Modern Preparation of TCM, Jiangxi University of Traditional Chinese Medicine, Ministry of Education, Nanchang 330004, China.
Ming
M
Yang
Sichuan University, Chengdu 610064, China.
Wenquan
W
Zou
Andrographolide; dissolution; evaluation; silicon; solid dispersion