Assay for the dianhydride of diethylenetriaminepentaacetic acid and its major degradation products by capillary electrophoresis.
DTPA-DA, the dianhydride of diethylenetriaminepentaacetic acid (DTPA), is a drug intermediate used for preparing functional derivatives of the DTPA metal chelator as well as for coupling DTPA to polypeptides, antibodies and other macromolecules. The DTPA functions as a complexing agent for various types of metal ions or radionuclides for diagnostic as well as therapeutic applications. A capillary electrophoretic (CE) method has been developed to assess the purity of DTPA-DA. The method involves derivatization of the DTPA-DA to form a diamide and subsequent complexation of the diamide with Zn2+ followed by free solution CE with UV absorbance detection at 200 nm. The procedure is capable of separating and quantitating the two major degradation products of DTPA-DA, the monoanhydride (DTPA-MA) and the free pentaacetic acid (DTPA). The method was validated with respect to linearity, precision/reproducibility, limit of detection and accuracy. This procedure was shown to be a fast and reliable method to assay this highly reactive drug intermediate.
Bullock
J
J
Sanofi-Winthrop Pharmaceuticals Research Division, Collegeville, PA 19426, USA.
D000812:Anhydrides / Q000032:analysis*; D019075:Electrophoresis, Capillary / Q000379:methods*; D004369:Pentetic Acid / Q000737:chemistry*; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet
D000812:Anhydrides; D004369:Pentetic Acid