The stabilization of amorphous zopiclone in an amorphous solid dispersion
Abstract
Zopiclone is a poorly soluble psychotherapeutic agent. The aim of this study was to prepare and
characterize an amorphous form of zopiclone as well as the characterization and performance of a stable
amorphous solid dispersion. The amorphous form was prepared by the well-known method of quenchcooling
of the melt. The solid dispersion was prepared by a solvent evaporation method of zopiclone,
polyvinylpyrrolidone-25 (PVP-25), and methanol, followed by freeze-drying. The physico-chemical properties
and stability of amorphous zopiclone and the solid dispersion was studied using differential scanning
calorimetry (DSC), infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron
microscopy (SEM), hot-stage microscopy (HSM), X-ray diffractometry (XRD), solubility, and dissolution
studies. The zopiclone amorphous solid-state form was determined to be a fragile glass; it was concluded
that the stability of the amorphous form is influenced by both temperature and water. Exposure of
amorphous zopiclone to moisture results in rapid transformation of the amorphous form to the crystalline
dihydrated form. In comparison, the amorphous solid dispersion proved to be more stable with increased
aqueous solubility
URI
http://hdl.handle.net/10394/18012https://link.springer.com/article/10.1208%2Fs12249-015-0302-4
https://doi.org/10.1208/s12249-015-0302-4
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- Faculty of Health Sciences [2404]