ABSTRACT
We have examined the synthesis of hydroxybutenyl cyclomaltooligosaccharides (cyclodextrins) and the ability of these cyclodextrin ethers to form guest-host complexes with guest molecules. The hydroxybutenyl cyclodextrin ethers were prepared by a base-catalyzed reaction of 3,4-epoxy-1-butene with the parent cyclodextrins in an aqueous medium. Reaction byproducts were removed by nanofiltration before the hydroxybutenyl cyclodextrins were isolated by co-evaporation of water-EtOH. Hydroxybutenyl cyclodextrins containing no unsubstituted parent cyclodextrin typically have a degree of substitution of 2-4 and a molar substitution of 4-7. These hydroxybutenyl cyclodextrins are randomly substituted, amorphous solids. The hydroxybutenyl cyclodextrin ethers were found to be highly water soluble. Complexes of HBen-beta-CD with glibenclamide and ibuprofen were prepared and isolated. In both cases, the guest content of the complexes was large, and a significant increase in the solubility of the free drug was observed. Dissolution of the complexes in pH 1.4 water was very rapid, and significant increases in the solubility of the free drugs were observed. Significantly, after reaching equilibrium concentration, a decrease in the drug concentration over time was not observed.
Subject(s)
Butanols/chemistry , Butanols/chemical synthesis , Cyclodextrins/chemistry , Cyclodextrins/chemical synthesis , Oligosaccharides/chemistry , Oligosaccharides/chemical synthesis , Water/chemistry , Carbohydrate Sequence , Chromatography, High Pressure Liquid , Glyburide/analogs & derivatives , Glyburide/chemical synthesis , Glyburide/chemistry , Ibuprofen/analogs & derivatives , Ibuprofen/chemical synthesis , Ibuprofen/chemistry , Molecular Sequence Data , Nuclear Magnetic Resonance, Biomolecular , Solubility , Spectrometry, Mass, Matrix-Assisted Laser Desorption-IonizationABSTRACT
This review covers various aspects of microsensor technology with which we have been associated in our research program. Current work deals with the development of new coatings for use on surface acoustic wave (SAW) devices for both resistance and frequency-based measurements. The microsensor area is currently a small but rapidly expanding field that involves diverse disciplines, including synthetic and polymer chemistry, analytical chemistry, surface science, computer science, and electronic engineering. We have attempted to assist the reader by describing various other facets while highlighting the development of new microsensor coatings. These facets include the way in which the synthetic chemistry is guided by requirements of coating technology and surface science and notes on the use of sophisticated electronic devices and data manipulation techniques to evaluate the compounds synthesized.