Use of solubilizing agents to study radiosensitization in vitro by compounds of low water solubility.

A major disadvantage in studying the effects of chemicals on the radiation response of mammalian cells in vitro can be the poor water solubility of the chemicals. Using Chinese hamster cells we have overcome this problem by using dimethyl sulphoxide and ethanol as co-solvents. From studies using these co-solvents and misonidazole as a standard we have demonstrated that these co-solvents have no effect on sensitizing efficiency and cytotoxicity. A number of poorly water soluble 2-nitroimidazoles of promising structure have been studied. The results, together with those from studies on misonidazole and the co-solvents are presented.