Chemistry Reference
In-Depth Information
Figure 4.2.
Expanded regions of the IR spectra of solid dispersions of indomethacin in PVP
displaying the carbonyl band region, shown in comparison with physical mixtures of amorphous
indomethacin with PVP. The spectra were obtained by transmission IR spectroscopy using KBr
pellets containing approximately 1% of the sample. The percentages correspond to the amount
of PVP present in the sample, with 0% corresponding to pure amorphous indomethacin and
100% corresponding to pure PVP. (Reproduced with permission from Ref. 60. Copyright 1997,
Plenum Publishing and Springer.)
of the IR spectra obtained for indomethacin dispersions in PVP over a wide concentration
range are shown in comparison with physical mixtures of separately prepared amorphous
drug and PVP produced by powder blending [60]. The changes in carbonyl band
structure in the dispersion can be related to hydrogen bonding between the drug and the
polymer. Other studies have employed transmission IR spectroscopy of thin dispersion
films to observe drug
-
polymer interactions in dispersions consisting of nifedipine
-
PVP,
ketoprofen
PVP [61]. The use of IR spectroscopy
in this manner is a powerful and popular method to characterize dispersions, but is
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PVP, droperidol
-
PVP, and pimozide
-
