Stability of tacrolimus injection diluted in 0.9% sodium chloride injection and stored in Excel bags.

Purpose. The chemical stability and physical compatibility of tacrolimus i.v. infusion solutions prepared in Excel bags and stored at 23 or 4 degrees C for up to nine days were studied. Methods. Tacrolimus admixtures (2, 4, and 8 mu g/mL) were prepared in Excel bags using 0.9% sodium chloride injection and stored at 23 degrees C without protection from light or at 4 degrees C in the dark. Test samples were withdrawn from triplicate bag solutions immediately after preparation and at predetermined time intervals (1, 3, 5, 7, and 9 days). Chemical stability was assessed by measuring tacrolimus concentrations using a validated stability indicating high-performance liquid chromatography assay. The physical stability of the admixtures was assessed by visual examination and by measuring turbidity, particle size, and drug content. Results. All test solutions stored at 23 or 4 degrees C had a no greater than 6% loss of the initial tacrolimus concentration throughout the nine-day study period. All test samples of tacrolimus admixtures, under both storage conditions, were without precipitation and remained clear initially and throughout the nine-day observation period. Changes in turbidities were minor; measured particulates remained few in number in all samples throughout the study. Conclusion. Extemporaneously prepared infusion solutions of tacrolimus 2, 4, and 8 mu g/mL in 0.9% sodium chloride injection in Excel bags were chemically and physically stable for at least nine days when stored at room temperature (23 degrees C) without protection from light and when stored in a refrigerator (4 degrees C) in the dark.