Effects of different treatment schedules of free and liposomal prednisolone phosphate on tumor growth. The formulations were injected at a dose of 20 mg/kg on days 1, 7, and 14 (A and B), or as a single injection on day 7 (C and D) or day 14 (E and F) in B16.F10 tumor-bearing mice (A, C, and E) or C26 tumor-bearing mice (B, D, and F). Mean ± SD; n = 5 animals per experimental group.