Pharmaceutical development of a parenteral lyophilized formulation of the novel indoloquinone antitumor agent EO9

The aim of this study was to design a stable parenteral dosing form of the investigational cytotoxic drug, encoded EO9. EO9 exhibits poor aqueous solubility and stability characteristics. Freeze-drying was selected as the manufacturing process. Differential scanning calorimetry studies were conducted to determine the freezedrying cycle parameters. A stable lyophilized formulation of EO9 was developed. The prototype, containing 8.0 mg EO9 and 200 mg lactose/vial, was found to be the optimal formulation in terms of solubility, length of the freezedrying cycle, stability, and dosing requirements for phase I clinical trials. Quality control of the freeze-dried formulation showed that the manufacturing process does not change the integrity of EO9. Shelf-life studies demonstrated that the formulation remains stable for at least 1 year when stored at +4°C in a dark environment.