Novel Approach for the Purification and Analysis of Methotrexate-Branched Polymeric Polypeptide Conjugates by HPLC

Methotrexate (MTX) has been coupled to various structurally related, polycationic synthetic branched polypeptides containing a poly[L-Lys] backbone. We describe here a novel, rapid and simple RP-HPLC approach and its application for a) the monitoring of MTX-macromolecule conjugate synthesis, b) analysis of the composition of conjugates samples, c) semi-preparative purification of target compounds from reagents and side products, and d) stability studies of MTX-branched polypeptide conjugate samples.