Effect of pH and Additives on the Compatibility between Vancomycin and Furosemide Injections

抄録

　The physicochemical compatibility between injections of different agents is very important. An injection of the antibiotic vancomycin (VCM) is acidic and its standard pH range is 2.5-4.5. In clinical treatments, VCM injections are often used with Lasix^® (furosemide) injections. The Lasix^® injection is alkaline and its standard pH range is 8.6-9.6. Therefore, mixing VCM injections with Lasix^® injections may cause compatibility problems. We evaluated the effect of pH on the compatibility between VCM (original and two generic) and Lasix^® injections. Compatibility was not observed in non-pH-adjusted VCM with Lasix^® injections, but white crystals appeared when VCM injections adjusted to pH 2.5 experimentally were mixed with a Lasix^® injection, suggesting that the acidic condition of VCM injections cause compatibility. However, the residual rates of VCM did not change after 24 h in all mixtures. We analyzed the crystals by mass spectrometry and ¹H-NMR, and identified them to comprise furosemide.