STABILITY OF PIPERACILLIN SODIUM TAZOBACTAM SODIUM AND RANITIDINE HYDROCHLORIDE IN 0.9-PERCENT SODIUM-CHLORIDE INJECTION DURING SIMULATED Y-SITE ADMINISTRATION

The stability of piperacillin sodium plus tazobactam sodium and raniti dine hydrochloride in 0.9% sodium chloride injection during simulated Y-site administration was studied. Triplicate test solutions of pipera cillin 40 mg/mL plus tazobactam 5 mg/mL (as the sodium salts) or piper acillin 80 mg/mL plus tazobactam 10 mg/mL (as the sodium salts) were m ixed 1:1 with ranitidine 0.5 and 2.0 mg/mL (as the hydrochloride salt) . The solutions were stored at 23 degrees C, and samples were removed at zero, one, two, and four hours for measurement of drug concentratio n by stability-indicating high-performance liquid chromatography. At t he time of sampling and before any dilution, each sample was visually inspected for color and precipitation, and pH was determined. At all s ampling times, the concentrations of piperacillin, tazobactam, and ran itidine were >90% of initial concentrations. There were no substantial changes in pH or color. Tazobactam 5 mg/mL (as the sodium salt) and r anitidine 0.5 and 2 mg/mL (as the hydrochloride salt) in 0.9% sodium c hloride injection were stable for up to four hours during simulated Y- site administration. Piperacillin 80 mg/mL plus tazobactam 10 mg/mL (a s the sodium salts) and ranitidine 0.5 and 2 mg/mL (as the hydrochlori de salt) were stable for up to four hours during simulated Y-site admi nistration.