title: Inclusion of Paracetamol into β-cyclodextrin nanocavities in solution and in the solid state.
abstract: We report on steady-state UV-visible absorption and emission characteristics of Paracetamol, drug used as antipyretic agent, in water and within cyclodextrins (CDs): β-CD, 2-hydroxypropyl-β-CD (HP-β-CD) and 2,6-dimethyl-β-CD (Me-β-CD). The results reveal that Paracetamol forms a 1:1 inclusion complex with CD. Upon encapsulation, the emission intensity enhances, indicating a confinement effect of the nanocages on the photophysical behavior of the drug. Due to its methyl groups, the Me-β-CD shows the largest effect for the drug. The observed binding constant showing the following trend: Me-β-CD>HP-β-CD>β-CD. The less complexing effectiveness of HP-β-CD is due to the steric effect of the hydroxypropyl-substituents, which can hamper the inclusion of the guest molecules. The solid state inclusion complex was prepared by co-precipitation method and its characterization was investigated by Fourier transform infrared spectroscopy, 1H NMR and X-ray diffractometry. These approaches indicated that Paracetamol was able to form an inclusion complex with CDs, and the inclusion compounds exhibited different spectroscopic features and properties from Paracetamol.
authors.affiliation: Nanochemistry Laboratory, Chemistry Department, Faculty of Science, Kafrelsheikh University, 33516 Kafr ElSheikh, Egypt. elkemary@yahoo.com
authors.forename: Maged
authors.initials: M
authors.lastname: El-Kemary
authors.forename: Saffaa
authors.initials: S
authors.lastname: Sobhy
authors.forename: Samy
authors.initials: S
authors.lastname: El-Daly
authors.forename: Ayman
authors.initials: A
authors.lastname: Abdel-Shafi
mesh_terms: D000082:Acetaminophen / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D009682:Magnetic Resonance Spectroscopy; D049329:Nanostructures / Q000737:chemistry*; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D012996:Solutions; D047392:beta-Cyclodextrins; D000082:Acetaminophen