Proton nuclear magnetic resonance spectroscopy studies of the inclusion complex of piroxicam with beta-cyclodextrin.
Proton nuclear magnetic resonance spectroscopy showed that piroxicam sodium salt forms an inclusion complex with beta-cyclodextrin in aqueous solution. The 1:1 stoichiometry of the complex was determined by the continuous variation method. Significant nuclear Overhauser effects were observed between the inner protons of beta-cyclodextrin and protons of both the aromatic rings of piroxicam sodium salt, a result indicating that two isomeric 1:1 complexes must be present in solution within the range of concentrations investigated. The overall association constant was 113 M at 298 K. At concentrations less than 1.0 x 10(-3) M, the complex is completely dissociated.
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CNR-Centro per lo Studio delle Sostanze Organiche Naturali, c/o Chemistry Department, Milano, Italy.
Mele
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Redenti
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Ventura
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D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003505:Cyclodextrins / Q000737:chemistry*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D010894:Piroxicam / Q000737:chemistry*; D013057:Spectrum Analysis; D047392:beta-Cyclodextrins
D003505:Cyclodextrins; D047392:beta-Cyclodextrins; D010894:Piroxicam; C031215:betadex