We have compared the in vitro activity of N-trifluoroacetyladriamycin-14-valerate (AD-32) and doxorubicin hydrochloride (ADR) on the clonal growth of human bladder tumor cell lines (HBTCL). In order to determine the relatively toxicity of ADR and AD-32 on hematopoietic stem cells, CFU-GM assays were set up using 10 normal human bone marrow samples. The mean lethal dose for 50% of the colonies (LD-50) for ADR was 1.6 +/- 1.4 microM and that for AD-32, 3.9 +/- 4.9 microM (P less than 0.55), suggesting that these agents have similar bone marrow toxicity. Both drugs produced enhanced inhibition of clonal growth of HBTCL with increasing C X Ts. The spectrum of activity of the two drugs was similar against a panel of seven HBTCL. The activity of ADR was inhibited at 4 degrees C while the activity of AD-32 was unaffected by temperature. ADR was more effective against HBTCL in the log growth phase than the plateau phase while the reverse was found using AD-32. Verapamil was found to enhance the activity of both ADR and AD-32 against a HBTCL (T24), found to be resistant to both agents. The lipophilic properties of AD-32, along with its enhanced activity when used over prolonged periods of time and its activity against tumor cells in the plateau phase, suggest that AD-32 could be useful in the management of patients with superficial bladder cancer.