ISSN:
0899-0042
Keywords:
(-)-(S)-scopolamine
;
(-)-(S)-hyoscyamine
;
racemization
;
hydrolysis
;
α-cyclodextrins
;
β-cyclodextrins
;
γ-cyclodextrins
;
β-cyclodextrin derivatives
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Because of the constantly increasing demand for optically pure drugs it is of great importance to elucidate factors affecting stereochemistry, in order to provide a stable formulation with a high chiral quality of the desired isomer. Therefore, the effects of cyclodextrins (CyDs) and their alkylated and hydroxyalkylated derivatives on racemization and hydrolysis of (-)-(S)-hyoscyamine and (-)-(S)-scopolamine were examined kinetically and spectroscopically (NMR). Direct methods, based on a chiral and achiral chromatographic phase system, were used to determine their degradation products and enantiomer composition during stability tests. All different CyDs, except α-CyD, retarded racemization and hydrolysis. The inclusion of the drug substances in CyDs inhibits the attack of hydroxyl ions and/or water molecules and thus retards the racemization and hydrolysis. The racemization of the tropic acid alkaloids is dependent on the pH and temperature. NMR studies were used to evidence the formation of a soluble 1:1 complex in aqueous solution. © 1993 Wiley-Liss, Inc.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/chir.530050207
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