A new polymorph of acetohexamide (Form VI) was prepared via the formation of a complex with 2-hydoxybutyl-β-cyclodextrin (HB-β-CD) in aqueous solution. An alkaline solution of acetohexamide and HB-β-CD was adjusted to pH 4.0 by titration with hydrochloric acid. The resulting opaque solution was filtered through paper and allowed to stand at 4°C for 24h. The resulting precipitate was isolated on a filter and analyzed for polymorph content by powder X-ray diffractometry and thermal analysis. The diffraction pattern and thermal behavior of the precipitate was different from those of previously reported acetohexamide polymorphs (Forms I, III, IV and V), indicating that a new polymorph of the drug, i.e. Form VI was produced. This new polymorph was fairly stable against conversion to a stable form even at accelerated storage conditions. Crystalline Form VI was highly soluble in water and dissolved more rapidly than the other known polymorphs. This property was reflected in the blood concentrations of the drug after oral administration to rats.
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http://dx.doi.org/10.1016/j.ijpharm.2013.06.026 | DOI Listing |
Chem Pharm Bull (Tokyo)
October 2019
Faculty of Pharmaceutical Sciences, Sojo University.
Int J Pharm
September 2013
Faculty of Pharmacy, King Abdulaziz University, 80260, Jeddah 21589, Saudi Arabia.
A new polymorph of acetohexamide (Form VI) was prepared via the formation of a complex with 2-hydoxybutyl-β-cyclodextrin (HB-β-CD) in aqueous solution. An alkaline solution of acetohexamide and HB-β-CD was adjusted to pH 4.0 by titration with hydrochloric acid.
View Article and Find Full Text PDFJ Pharm Sci
July 2000
Lilly Research Laboratories, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, Indiana 46285, USA.
Recent advances in crystallographic computing have made it possible to solve by powder diffraction methods structures that have not been possible to solve by single-crystal methods. Although there is vast improvement in the quality of data obtained from high-intensity synchrotron radiation, we found that surprisingly reliable results can be obtained from conventional laboratory sources. In this article we examine the application of Monte Carlo/simulated annealing methods for the determination of structures ranging in complexity from 9 to 15 degrees of freedom.
View Article and Find Full Text PDFJ Pharm Pharmacol
April 1989
Welsh School of Pharmacy, University of Wales College of Cardiff, UK.
Infrared data determined for known polymorphic forms and some new derivatives of acetohexamide and related compounds support the view that acetohexamide polymorphs exhibit keto-enol tautomerism. They indicate that type A polymorphs exist in the enol form, probably stabilized by intramolecular bonding between an O-H and S = O group to form a six-membered ring. Type B polymorphs exist in the keto form with the urea carbonyl group intermolecularly bonded to a sulphonamide N-H.
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