Rapid Miniaturized Chromatography Procedures for Iodinated Monoclonal Antibodies: Comparison to Gel Exclusion Chromatography

Abstract

Chromatographic quality control testing of radioiodinated monoclonal antibodies (¹³¹I MOAB) is necessary to assess radiochemical purity prior to patient injection. Conventional gel exclusion chromatography column scanning (GCS) is time consuming and not practical. We investigated rapid miniaturized chromatographic procedures for evaluating the radiochemical purity of ¹³¹I MOAB. Three systems were evaluated using Gelman ITLC-SG and three solvents: acetone, 85% methanol, and 0.9% NaCl. Radiochemical analysis was performed on Na¹³¹I of high radiochemical purity and Na¹³¹I containing radiochemical impurities, as well as three ¹³¹I MOAB preparations. Five separate measurements were obtained for each preparation and solvent, and the results were compared to GCS. The results demonstrated ITLC-SG and 0.9% NaCl was most accurate in assessing radiochemical purity when compared to GCS. With the ITLC-SG and acetone system, and to a lesser degree, the ITLC-SG and 85% methanol system, no separation between ¹³¹1 iodate/periodate and ¹³¹I MOAB was achieved, resulting in some instances in the overestimation of the radiochemical purity of the ¹³¹I MOAB.