Radioiodination of Cephalexin with ¹²⁵I and Its Biological Behavior in Mice

A.Abd El-Bary, A.M. Amin, A. El-wetery, S. Saad, M. Shoukry

.

DOI: 10.4236/pp.2012.31014                

Abstract

A procedure for radioiodination of Cephalexin with iodine-125 was carried out via an electrophilic substitution reaction. Using 3.7 MBq of Na¹²⁵I, 200μl of cephalexin as substrate, 200 μl of iodogen as oxidizing agent in acetone at 40°C for 20 min, a maximum radiochemical yield of ¹²⁵I-Ceph (95%) was obtained. The labeled compound was separated and purified by means of high-pressure liquid chromatography (HPLC). The biological distribution in normal and inflamed (septic and aseptic) mice indicates the suitability of radioiodinated cephalexin for imaging of inflammation

Keywords

Cephalexin; Na¹²⁵I; Electrophilic Substitution Reaction; Radioiodination; Inflammation

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	W. Sneader, “Cephalosporin Analogues,” Wiley, 2005, New York, p. 324. doi:10.1002/0470015535
[2]	The American Society of Health-System Pharmacists, “Cephalexin,” Retrieved 3 April 2011. http://www.drugs.com/monograph/cephalexin.html
[3]	M. E. Pichichero, “Use of Selected Cephalosporins in Penicillin-Allergic Patients: A Paradigm Shift,” Diagnostic Microbiology and Infectious Disease, Vol. 57, No. 3, 2007, pp. 13S-18S. doi:10.1016/j.diagmicrobio.2006.12.004
[4]	F. Rojo, J. A. Ayala, E. J. de la Rosa , M. A. de Pedro, V. Arán, J. Berenguer and D. Vázquez, “Binding of 125I- Labeled Beta-Lactam Antibiotics to the Penicillin Binding Proteins of Escherichia Coli,” Journal of Antibiotics (Tokyo), Vol. 37, No. 4, 1984, pp. 389-393.
[5]	D. A. Spyker, B. L. Thomas, M. A. Sande and W. K. Bolton, “Pharmacokinetics of Cefaclor and Cephalexin: Dosage Nomograms for Impaired Renal Function,” Antimicrob Agents Chemother, Vol. 14, No. 2, 1978, pp. 172-177.
[6]	V. M. Shinde, B. S. Desai and N. M. Tendolkar, Indian Journal of Pharmaceutical Sciences, Vol. 56, No. 2, 1994, pp. 58-60.
[7]	K. M. El-Azony, A. A. El-Mohty, H. M Killa., U. Seddik, and S. I. Khater, “An Investigation of the 125I-Radioiodination of Colchicine for Medical Purposes,” Journal of Labelled, Compounds and Radiopharmaceuticals, Vol. 52, No. 1, 2008, pp. 1-5.
[8]	E. A. EL-Ghany, R. El-Sheikh, A. S. El-Wetery, A. Z. Saleh and H. Hussien, Arab Journal of Nuclear Sciences and Applications, Vol. 42, 2007, pp. 80.
[9]	W. M. Hunter, Proceedings of the Society for Experimental Biology and Medicine, Vol. 133, 1970, pp. 989.
[10]	V. Nara, V. Howell, R. Harapanhali, K. Sastry and D. Rao, Journal of Nuclear Medicine, Vol. 33, 1992, pp. 2196.
[11]	W. G. Wood, C. Wachter and P. C. Scriba, “Comparison of 125I-Labelling of Polypeptides Using Chloramine-T and 1,3,4,6-Tetrachloro-3α,6α-diphenyl-glycoluril (Iodogen?) with Subsequent Separation of Iodide and Labelled Protein on Cation-Exchange Dextran,” Fresenius’ Journal of Analytical Chemistry, Vol. 301, No. 2, 1980, p. 119. doi:10.1007/BF00467765
[12]	K. M. El-Azony, Arab Journal of Nuclear Sciences and Applications, Vol. 37, 2004, pp. 81.
[13]	H. R. Adams, “Veterinary Pharmacology and Therapeutic,” 8th Edition, Wiley-Blackwell, New York, 2001, p. 21.
[14]	J. C. Saccavini, C. Bruneau, IAEA-CN 4519, 1984, pp. 153.
[15]	R. F. Verbruggen,“Kit Preparation and Rapid Quality Control of I-Labelled Hippuran,” International Journal of Radiation Applications and Instrumentation. Part A. Applied Radiation and Isotopes, Vol. 37, No. 12, 1986, pp. 1249-1250. doi:10.1016/0883-2889(86)90017-1
[16]	J. A. Davies and J. M. Holt, “Clinical Pharmacology of Cephalexin Administered by Intravenous Injection,” Journal of Clinical Pathology, Vol. 25, No. 6, 1972, pp. 518-520. doi:10.1136/jcp.25.6.518