Stability of labetalol hydrochloride with selected critical care drugs during simulated Y-site injection

Abstract

The compatibility and stability of labetalol hydrochloride in combination with various critical care drugs was evaluated. Labetalol hydrochloride 1.0 mg/mL was combined in 5% dextrose injection with equal volumes of each of the following drugs: dobutamine 2.5 mg/mL (as the hydrochloride salt), dopamine hydrochloride 1.6 mg/mL, morphine sulfate 0.5 mg/mL, nitroglycerin 0.2 mg/mL, and ranitidine 0.6 mg/mL (as the hydrochloride salt). The mixtures were placed in duplicate Y-site administration sets. Visual inspection, pH determination, and high-performance liquid chromatography were performed in duplicate on samples removed at zero, two, and four hours. No change in pH or appearance occurred throughout the study. All drug concentrations remained above 90% of the initial concentration in each combination. Labetalol hydrochloride 1.0 mg/mL and dobutamine 2.5 mg/mL (as the hydrochloride salt), dopamine hydrochloride 1.6 mg/mL, morphine sulfate 0.5 mg/mL, nitroglycerin 0.2 mg/mL, or ranitidine 0.6 mg/mL (as the hydrochloride salt) in 5% dextrose injection were stable and compatible for up to four hours at 20-25 degrees C during simulated Y-site injection.