Establishment of Quality Standard for Metaiodobenzylguanidine as Radiopharmaceutical Precursor

Meta-iodobenzylguanidine (MIBG) is used as a chemical precursor of radioiodinated (¹²³I or ¹³¹I) MIBG preparation. In order to control the quality of MIBG, in this study, Infrared identification of self-made MIBG was carried out, the physical and chemical properties of solubility, pH, melting point and drying weight loss were determined, the content of elemental impurities was determined by ICP-MS, the headspace gas chromatography of residual solvent was established, and the content and related substances were determined by HPLC were established. The results for multiple batches of MIBG analysis showed that they met the requirements for medicinal precursors, the infrared spectrum of MIBG was consistent with that of the reference substance, the pH was in the range of 4.0-6.0, the melting point was 167-170 ℃, and the drying weight loss was less than 0.3%; ethanol residue was less than 0.5%, the content of elemental impurities was lower than the control threshold, together with no related impurities detected, and the contents of MIBG were 98.0%-102.0%. The quality standard of MIBG established in this study provides and provided basis for the quality control of MIBG.