Determination methods for the anticancer drug dicycloplatin, a supramolecule assembled through hydrogen bonding

Dicycloplatin is a new generation supramolecular platinum-containing anti-cancer drug. Due to its structure, it is difficult to differentiate dicycloplatin from physical mixtures of carboplatin and cyclobutane dicarboxylate, and confounding results may arise during drug characterization. To solve this problem, this study aims to provide a reliable and reproducible standard for the determination of dicycloplatin. A simple method for dicycloplatin quality control has been developed using X-ray powder diffraction (XRPD) and high performance liquid chromatography (HPLC). XRPD allowed the control of impurities and dissociation of the dicycloplatin active ingredient to less than 1%, and HPLC allowed the monitoring and control of the relative molar ratio of carboplatin and cyclobutane dicarboxylate within the purity range. The study proved for the first time that the dicycloplatin supramolecule is substantially different from a physical mixture of carboplatin and cyclobutane dicarboxylate.