Study on β‐cyclodextrin grafting with chitosan and slow release of its inclusion complex with radioactive iodine

Abstract

Abstract β‐CD‐2‐CTS was synthesized by β‐cyclodextrin reacting with p ‐toluenesulfonyl chloride, then grafting with chitosan. The infrared spectra analysis and 13 C NMR confirmed that β‐cyclodextrin reacted with p ‐toluenesulfonyl chloride at the 2‐position carbon atom in the substituted glucose unit of β‐cyclodextrin and formed β‐CD‐2‐OTs. In the 13 C NMR of β‐CD‐2‐OTs, the characteristic peak of the 2‐postion carbon atom in the substituted glucose unit of β‐cyclodextrin appeared at 78.43 ppm. β‐CD‐2‐CTS was characterized with infrared spectra analysis and X‐ray diffraction. In the infrared spectra of β‐CD‐2‐CTS, the characteristic peak of α‐pyanyl vibration of β‐CD was at 848.6 cm −1 . The characteristic peak of β‐pyanyl vibration of CTS was at 894.9 cm −1 . The X‐ray diffraction analysis showed that the peak at 2θ = 20° decreased greatly in β‐CD‐2‐CTS. The polymer inclusion complex of β‐CD‐2‐CTS with iodine was prepared and its inclusion ability was studied. The experimental results showed that a nice bit of iodine was included with β‐CD‐2‐CTS and formed a stable inclusion complex. After the subcutaneous implantation of the polymer inclusion complex of β‐CD‐2‐CTS with 131 I 2 in rats, 131 I 2 exhibited the property of slow release. 131 I 2 in the blood of rats decreased slowly. 131 I 2 in the blood of rats maintained approximately half of maximum for 70 days later, and maintained much higher radioactivity in the organs of rats compared to the inclusion complex of β‐CD with 131 I 2 , too. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2414–2421, 2001