Compatibility and stability of seven selected cephalosporin antibiotics during extended infusion

ObjectiveTo investigate the physical and chemical stability of cefminox sodium, cefuroxime sodium, cefoxitin sodium, ceftizoxime sodium, cefmetazole sodium, ceftazidime and cefamandole nafate when continuously infused with 0.9% sodium chloride (NS) and 5% glucose (GS).MethodsSeven cephalosporin antibiotics were reconstituted in 50 and 100 mL of NS and GS, and stored at room temperature. Samples were collected at 0, 2, 4, 8, and 24 hours to evaluate changes in appearance, pH, insoluble particle count, and drug content.ResultsThe admixture solutions of cefuroxime with both solvents turned yellow at 8 hours. The relative percentage content of the low-concentration group in NS dropped to 82.97% at 24 hours. When cefamandole nafate was admixed with NS, contents of both high and low concentrations dropped below 90% at 8 hours and below 60% at 24 hours. The pH change of the high-concentration group exceeded 1.0 pH unit at 24 hours. For cefoxitin sodium, the pH change of all concentration groups admixed with both solvents exceeded 1.0 pH unit at 24 hours. The high-concentration group in NS declined to 87.72%. The admixture solutions of cefminox with both solvents showed slight discoloration at 24 hours. When cefminox was admixed with GS, the contents of both concentration groups dropped below 90% at 2 hours. All other drug-solvent-concentration combinations had all indicators within the specified limits.ConclusionWhen admixed with NS, cefmetazole, ceftazidime, and ceftizoxime are stable for 24 hours continuous infusion; cefoxitin and cefminox for up to 8 hours; and cefuroxime and cefamandole nafate for 4 hours. When admixed with GS, cefmetazole, ceftazidime, and ceftizoxime are stable for 24 hours; cefoxitin for up to 8 hours; cefuroxime for 4 hours; and cefminox has a stability period of less than 2 hours, so GS is not recommended as it is continuous infusion solvent.