Home About us Contact
|
Home About us Contact | ||
|
|
||
Cyclodextrin Inclusion Complex (cyclodextrin + inclusion_complex)
Selected AbstractsCyclodextrin inclusion complexes as novel MOCVD precursors for potential cobalt oxide depositionAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 2 2010N. D. Papadopoulos Abstract The potential use of the inclusion complexes of ,-cyclodextrins with metal halides as novel precursors in MOCVD applications was examined in terms of microstructure, thermal stability and chemical modifications during heating. The investigation was especially focused on the inclusion complex of ,-cyclodextrin with cobalt iodide for cobalt oxide thin film deposition. The general composition assigned to the dextrin's inclusion complex was: (,-CD)2,CoI7,11H2O. It was found that the inclusion complex of ,-cyclodextrin with CoI2 may prove a promising alternative to traditional metalorganic or organometallic Co-precursors for precise CVD applications. The sublimation temperature must be preferably in the range 70,125 °C, and the decomposition temperature (substrate temperature) in the range of 350,400 °C. Three distinct regions can be recognized by heating: transformation of tightly bound water molecules into easily movable ones, sublimation of iodine ions and Co atoms oscillation and thermal decomposition of the glycositic ring into volatile by-products. Copyright © 2009 John Wiley & Sons, Ltd. [source] Catalytic Polymerizations of Hydrophobic, Substituted, Acetylene Monomers in an Aqueous Medium by Using a Monomer/Hydroxypropyl- , -cyclodextrin Inclusion ComplexMACROMOLECULAR RAPID COMMUNICATIONS, Issue 2 2009Lei Ding Abstract Ten hydrophobic, substituted, acetylene monomers were examined as to their abilities to form an inclusion complex with hydroxypropyl- , -cyclodextrin (HPCD). Only the monomers with suitable substitutents were found to form the monomer/HPCD complex, which was identified by NMR, FTIR, and UV-vis spectroscopy. Polymerizations of the monomers were successfully carried out in aqueous solution by using the prepared monomer/HPCD inclusion complex and by using a water-soluble Rh-based catalyst, [Rh(cod)2BF4] or [Rh(nbd)(H2O)OTs]. Such polymerizations provided high-yield (>90%) polymers with a cis content of approximately 100%. The as-prepared polymers could take an ordered helical conformation, just like their counterparts obtained in organic solvents. [source] Piroxicam/2-hydroxypropyl-,-cyclodextrin inclusion complex prepared by a new fluid-bed coating techniqueJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 2 2009Xingwang Zhang Abstract This work was aimed at investigating the feasibility of fluid-bed coating as a new method to prepare cyclodextrin inclusion complex. The inclusion complex of the model drug piroxicam (PIX) and 2-hydroxypropyl-,-cyclodextrin (HPCD) in aqueous ethanol solution was sprayed and deposited onto the surface of the pellet substrate upon removal of the solvent. The coating process was fluent with high coating efficiency. Scanning electron microscopy revealed a coarse pellet surface, and a loosely packed coating structure. Significantly enhanced dissolution, over 90% at 5 min, was observed at stoichiometric PIX/HPCD molar ratio (1/1) and at a ratio with excessive HPCD (1/2). Differential scanning calorimetry and powder X-ray diffractometry confirmed absence of crystallinity of PIX at PIX/HPCD molar ratio of 1/1 and 1/2. Fourier transform-infrared spectrometry and Raman spectrometry revealed interaction between PIX and HPCD adding evidence on inclusion of PIX moieties into HPCD cavities. Solid-state 13C NMR spectrometry indicated possible inclusion of PIX through the pyridine ring. It is concluded that fluid-bed coating has potential to be used as a new technique to prepare cyclodextrin inclusion complex. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:665,675, 2009 [source] | ||||||||||