Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5420566 | Solid State Nuclear Magnetic Resonance | 2010 | 7 Pages |
Abstract
The polymorphic forms of lactose in alcoholic suspensions have been determined by 13C CP-MAS NMR spectroscopy, employing hand-made glass inserts. Suspensions of alpha lactose monohydrate (Lα·H2O) with particle size between 2 and 200 μm were prepared by 24 h reflux or by storage for 28 d in anhydrous ethanol without agitation. These suspensions were compared to an ethanolic sub-micron lactose suspension provided by a 3 M Health Care (Loughborough). The 13C CP-MAS NMR spectra indicated that Lα·H2O dehydrated to stable anhydrous alpha lactose polymorph (LαS) whilst suspended in ethanol. In addition, strong ethanol 13C resonances were observed for some samples, indicating a liquid-solid interaction between the ethanol and lactose surface. Replacement of ethanol with anhydrous methanol, n-butanol and 3-methylbutan-2-ol implied that the solvent mediated dehydration of Lα·H2O to LαS occurs as a result of sterically controlled interactions.
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Physical and Theoretical Chemistry
Authors
J.L. Crisp, S.E. Dann, M. Edgar, C.G. Blatchford,