Inclusion of Paracetamol into β-cyclodextrin nanocavities in solution and in the solid state

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• 作者：Maged El-Kemary^a ; ^{elkemary@yahoo.com" rel="nofollow} ; Saffaa Sobhy^a ; Samy El-Daly^b ; Ayman Abdel-Shafi^c
• 关键词：Paracetamol ; &#x3b2 ; -Cyclodextrin ; Hydroxypropyl-&#x3b2 ; -cyclodextrin ; Methyl-&#x3b2 ; -CD ; Inclusion complex
• 刊名：Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
• 出版年：2011
• 出版时间：September 2011
• 年：2011
• 卷：79
• 期：5
• 页码：1904-1908
• 全文大小：663 K
• ISSN：S138614251100463X

文摘

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.