THE CHEMICAL NATURE, PURITY AND STABILITY OF DIETHYL-3-IODOPHENYLCARBAMOYLMETHYL)-IMINODIACETIC ACID

The chemical purity and stability of a radio pharmaceutical ethyl-3-io do-phenyl-carbamoylmethyl)-iminodiacetic acid (IODIDA) has been studie d using HPLC. The HPLC results indicate that IODIDA decomposed into at least three species after 99mTc labelling, and the amount of these va ried with time. Mass spectra obtained by negative ion FABMS of no-carr ier-added (NCA) Tc-labelled IODIDA showed, in addition to the molecula r ion and the sodium adduct of iethyl-3-iodo-phenylcarbamoylmethyl)-im inodiacetic acid, peaks corresponding to sodium containing dimers, tri mers and tetramers. Several peaks were also found that may be assigned to 99Tc(I) containing dimers, trimers and tetramers.