Chemical and physical stability of etoposide and teniposide in commonly used infusion fluids.

The chemical and physical stabilities of the cytotoxic drugs etoposide and teniposide have been investigated in three different, commonly used, infusion fluids. Chemical stability has been measured by a stability indicating reversed-phase high-performance liquid chromatographic assay with ultraviolet detection. Physical stability was checked by visual inspection and the presence of microparticles was inspected by viewing the admixtures against a white and dark background of a light box equipped with an incandescent lamp and a polarizing filter. Samples were also tested for changes in pH. It is concluded that etoposide and teniposide in 5% dextrose and 0.9% sodium chloride infusion fluids (concentration: 0.4 mg/mL) are chemically stable for at least four days at room temperature. Stability of the drugs is not influenced by the presence of normal room fluorescent light nor by the type of container material used (glass bottles or polyvinyl chloride minibags). Occasional precipitation occurred in etoposide infusion fluids with a concentration higher than 0.4 mg/mL. Teniposide infusion solutions were physically stable at the tested concentrations up to 0.7 mg/mL.