Highly stable indomethacin glasses resist uptake of water vapor.
Mass uptake of water vapor was measured as a function of relative humidity for indomethacin glasses prepared using physical vapor deposition at different substrate temperatures. Highly stable glasses were produced on substrates at 265 K (0.84Tg) by depositing at 0.2 nm/s while samples similar to melt-cooled glasses were produced at 315 K and 5 nm/s. Samples deposited at 315 K absorb approximately the same amount of water as glasses prepared by supercooling the melt while stable glasses absorb a factor of 5 less water. Unexpectedly, the diffusion of water in the stable glass samples is 5-10 times faster than in the glass prepared by cooling the liquid.
Dawson
Kevin J
KJ
Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Kearns
Kenneth L
KL
Ediger
M D
MD
Sacchetti
Mark J
MJ
Zografi
George D
GD
D004058:Diffusion; D005898:Glass / Q000737:chemistry*; D007213:Indomethacin / Q000737:chemistry*; D013696:Temperature; D014867:Water / Q000737:chemistry*
D014867:Water; D007213:Indomethacin