Compatible stability of methylprednisolone sodium succinate and tropisetron in 0.9% sodium chloride injection

Background A combination of methylprednisolone sodium succinate and tropisetron hydrochloride is commonly used to treat the nausea and vomiting associated with antineoplastic therapy. The objective of this study was to investigate the stability of tropisetron hydrochloride and methylprednisolone sodium succinate in 0.9% sodium chloride injection for up to 48hours. Methods Commercial solutions of methylprednisolone sodium succinate and tropisetron hydrochloride were obtained and further diluted with 0.9% sodium chloride injection to final concentrations of either 0.4 or 0.8mg/mL (methylprednisolone sodium succinate) and 0.05mg/mL (tropisetron). The admixtures were assessed for periods of up to 48hours after storage at 4 degrees C with protection from light and at 25 degrees C without protection from light. Physical compatibility was determined visually, and the chemical compatibility was measured with high-performance liquid chromatography (HPLC) and by measurement of pH values. Results HPLC analysis demonstrated that methylprednisolone sodium succinate and tropisetron hydrochloride in the various solutions were maintained at 97% of the initial concentrations or higher during the testing period. There were no changes observed by physical precipitation or pH in any of the prepared solutions. Conclusions Tropisetron hydrochloride injection and methylprednisolone sodium succinate injection in 0.9% sodium chloride injection are stable for up to 48hours at 4 degrees C and 25 degrees C.