title: Solvents effects on crystallinity and dissolution of β-artemether.
abstract: β-artemether (ARM) is a widely used anti-malarial drug isolated from the Chinese antimalarial plant, Artemisia annua. The solvent effects on crystal habits and dissolution of ARM were thoroughly investigated and discussed herein. The ARM was recrystallized in nine different solvents of varied polarity, namely, methanol, ethanol, isopropanol, tetrahydrofuran, dichloromethane, trichloromethane, ethyl acetate, acetone and hexane by solvent evaporation method. The obtained crystals were morphologically characterized using scanning electron microscope (SEM). The average sizes of crystals were 1.80-2.64 μm calculated from microscopic images using Image-Pro software. No significant change in chemical structure was noticed after recrystallization and the specific band at 875 cm-1wavenumber (C-O-O-C) confirmed the presence of most sensitive functional group in the ARM chemical structure. The existence and production of two polymorphic forms, polymorph A and polymorph B, was confirmed by differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD). The data suggested that the fabrication of polymorph B can be simply obtained from the recrystallization of ARM in a specific solvent. Significant effects of solvent polarity, crystals shapes and sizes on drug dissolution were noticed during in vitro dissolution test. The release kinetics were calculated and well fitted by the Higuchi and Hixon-Crowell models. The ARM-methanol and ARM-hexane showed highest and slowest dissolution, respectively, due to the effects of solvent polarity and crystal morphologies. Overall, proper selection of the solvents for the final crystallization of ARM helps to optimize dissolution and bioavailability for a better delivery of anti-malarial drug.
authors: a School of Pharmacy, Anhui University of Chinese Medicine , Hefei , China.|b Center for Drug Delivery System, Shanghai Institute of Materia Medica, Chinese Academy of Sciences , Shanghai , China.
authors: Jianghui
authors: J
authors: Xu
authors: b Center for Drug Delivery System, Shanghai Institute of Materia Medica, Chinese Academy of Sciences , Shanghai , China.
authors: Vikramjeet
authors: V
authors: Singh
authors: b Center for Drug Delivery System, Shanghai Institute of Materia Medica, Chinese Academy of Sciences , Shanghai , China.
authors: Xianzhen
authors: X
authors: Yin
authors: b Center for Drug Delivery System, Shanghai Institute of Materia Medica, Chinese Academy of Sciences , Shanghai , China.
authors: Parbeen
authors: P
authors: Singh
authors: b Center for Drug Delivery System, Shanghai Institute of Materia Medica, Chinese Academy of Sciences , Shanghai , China.
authors: Li
authors: L
authors: Wu
authors: c Department of Pharmaceutical Analysis , School of Pharmacy, Shenyang Pharmaceutical University , Shenyang , China.
authors: Xiaonan
authors: X
authors: Xu
authors: b Center for Drug Delivery System, Shanghai Institute of Materia Medica, Chinese Academy of Sciences , Shanghai , China.
authors: Tao
authors: T
authors: Guo
authors: c Department of Pharmaceutical Analysis , School of Pharmacy, Shenyang Pharmaceutical University , Shenyang , China.
authors: Lixin
authors: L
authors: Sun
authors: a School of Pharmacy, Anhui University of Chinese Medicine , Hefei , China.
authors: Shuangying
authors: S
authors: Gui
authors: a School of Pharmacy, Anhui University of Chinese Medicine , Hefei , China.|b Center for Drug Delivery System, Shanghai Institute of Materia Medica, Chinese Academy of Sciences , Shanghai , China.
authors: Jiwen
authors: J
authors: Zhang
mesh_terms: D000962:Antimalarials / Q000737:chemistry* / Q000378:metabolism; D000077549:Artemether; D037621:Artemisinins / Q000737:chemistry* / Q000378:metabolism; D002152:Calorimetry, Differential Scanning; D003460:Crystallization; D012995:Solubility; D012997:Solvents / Q000737:chemistry* / Q000378:metabolism; D014961:X-Ray Diffraction
chemical_list: D000962:Antimalarials; D037621:Artemisinins; D012997:Solvents; D000077549:Artemether
keywords: crystal habits; dissolution rate; polymorphic forms; recrystallization; β-artemether