Stability of cyclosporine with magnesium sulfate in 5% dextrose injection

The compatibility and stability of cyclosporine with magnesium sulfate in 5% dextrose injection was studied. Cyclosporine solution 50 mg/mL was added to each of three glass bottles containing magnesium sulfate injection and 5% dextrose injection; final theoretical concentrations of cyclosporine and magnesium sulfate were 2.0 mg/mL and 30 mg/mL, respectively. The samples were stored under fluorescent lighting at controlled room temperature (24 +/- 2.4 degrees C). At 6, 12, 24, and 36 hours each solution was visually inspected under normal lighting against a white and black background for color change, haze, or precipitation. Samples were assayed in duplicate for cyclosporine concentration by using a stability-indicating high-performance liquid chromatographic method. Turbidity occurred immediately after mixing but resolved in approximately 30 seconds. No other changes in clarity or color were noted. The admixtures retained > 90% of initial cyclosporine concentration for six hours, and there were no significant differences in mean cyclosporine concentrations among the individual samples. Cyclosporine 2.0 mg/mL added to magnesium sulfate 30 mg/mL in 5% dextrose injection was stable for six hours when stored in glass bottles at 24 degrees C under fluorescent lighting.