Authors: Geraldine Su, Ken Strassberger, Craig Kramer, Xinqun Huang, and Mike Markham
APT-76 is an anti-neoplastic agent and currently being developed as an extended-release formulation (enteric coating) for an ongoing early Phase 1 clinical trial. The finished drug product is a capsule filled with mini tablets. Two major issues related to impurities were encountered during the formulation and analytical stages:
1. Significant growth of a known impurity (DPI, Dephosphorylated Impurity, MH+ = 286) was observed. Use of pure alcoholic solvent, sonication, and temperature for extraction facilitates the formation of DPI.
2. Formation of an unknown impurity (Unk-3), which was above the qualification threshold (0.34% at release).
