Objective: To investigate the stability of 50 microg/ml tropisetron in 0.9% sodium chloride or 5% dextrose injections on storage in either 100 ml polyvinylchloride (Tuliflex) or polyolefin (Clear-flex) infusion bags, at +4 degrees C and -20 degrees C.
Method: A stability-indicating high-performance liquid chromatography (HPLC) assay was used to measure residual drug at day 0 (D0), D8, D15, D30, D60 and D90 for each bag. Samples were tested for pH at D0, D60 and D90. Frozen samples were thawed in a microwave oven according to a validated procedure before analysis.
Results: In 0.9% sodium chloride and 5% dextrose, no degradation products were observed in any of the chromatograms. No admixtures, at any time, contained less than 98.2% of the initial concentration. Only minor changes (-0.12 unit) in pH occurred over the storage period. No colour or other visual changes were seen in any sample.
Conclusion: Tropisetron (50 microg/ml) in either 0.9% sodium chloride or 5% dextrose is chemically stable in polyvinylchloride or polyolefin bags for at least 3 months when stored in a refrigerator or in a frozen state.