Amorphous polymer-water vapor interactions

Interactions between water vapor and amorphous pharmaceutical solids were evaluated using isothermal microcalorimetry. " The desorption of water from theophylline monohydrate has been investigated using microcalorimetric approaches.The properties of surfactants and surface-active drugs in solution were studied by Attwood et al. " using calorimetry, while titration microcalorimetry has been utilized to elucidate the nature of specific interactions in several pharmaceutical polymer-surfactants systems. " Drug decomposition was evaluated as a function of different... 

In this presentation, two examples of the use of vibrational spectroscopy to probe water-solid interactions in materials of interest to the food and pharmaceutical sciences are described. First, the interaction of water vapor with hydrophilic amorphous polymers has been investigated. Second, water accessibility in hydrated crystalline versus amorphous sugars has been probed using deuterium exchange. In both of these studies, Raman spectroscopy was used as the method of choice. Raman spectroscopy is especially useful of these types of studies as it is possible to control the environment of the sample more easily than with infrared spectroscopy. 

Fourier Transform Raman Spectroscopic Study of the Interaction of Water Vapor with Amorphous Polymers... 

Score values of the first principal component following analysis of the 1550 to 600 cm spectral region plotted against the mole fraction water. Source Reproduced from Taylor, L.S., Langkilde, F.W., and Zografi, G. Fourier transform Raman spectroscopic study of the interaction of water vapor with amorphous polymers, /. Pharm. Set., 90,888-901,2001. With permission of the copyright owner.)... 

Taylor LS, Langkilde FW, Zografi G (2001) Fourier transform Raman spectroscopic study of the interaction of water vapor with amorphous polymers. J Pharm Sd 90 888-901... 

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