Physical compatibility and chemical stability of bupivacaine, epinephrine, and nalbuphine in 0.45 % sodium chloride, 0.9 % sodium chloride, or plasma-lyte A.

Purpose: To evaluate the physical compatibility and chemical stability of the combination of bupivacaine, epinephrine, and nalbuphine when in mixed in 0.45 % sodium chloride, 0.9 % sodium chloride, or Plasma-Lyte A.

Methods: Bupivacaine 0.5 % (15 mL), epinephrine 1 mg/mL (0.15 mL), and nalbuphine 10 mg/mL (0.5 mL) were combined to prepare three distinct admixtures with 0.45 % sodium chloride, 0.9 % sodium chloride, or Plasma-Lyte A. Visual inspection, spectrophotometric analysis, pH evaluation, and high-performance liquid chromatography tests were conducted at hours 0, 1, 5, 8, and 24. Samples were stored in ambient room light at room temperature.

Results: There were no demonstrable changes identified in any of the samples with regards to visual changes, spectrophotometric absorbance, or pH. In each studied fluid, the remaining drug concentrations were an average of 100.92 % bupivacaine, 95.8 % epinephrine, and 100.02 % nalbuphine.

Conclusions: The combination of bupivacaine, epinephrine, and nalbuphine was found to be physically compatibility and chemically stable for a period of 24 h at room temperature.