OBJECTIVE: To investigate the stability of epirubicin bladder instillation, prepared from two different epirubicin formulations, under refrigerated storage, transportation and clinical use conditions. METHOD: A sequential study design was used. Epirubicin instillation (1 mg/mL) in polypropylene syringes was sequential incubated for periods of 84 days at 8 degrees C followed by 2 h at 25 degrees C and 1 h at 37 degrees C, the latter two temperatures replicating transport and intravesical conditions, respectively. RESULTS: The instillation was both chemically and physically stable under those incubation conditions. The formulation of epirubicin used to prepare the instillation infusions did not affect stability.