Alkalinization and precipitation characteristics of 0.2% ropivacaine

A laboratory evaluation that establishes the alkalinization characteristics of ropivacaine is a prerequisite for designing a clinical study of alkalinized ropivacaine. In our experiment, low doses of bicarbonate produced significant increases in the proportion of nonionized ropivacaine with only modest precipitation. There would be a low likelihood of substantial drug precipitation if the mixture was administered within 5 to 10 minutes after alkalinization. These results indicate that alkalinized ropivacaine should not be used for infusions and that ropivacaine should not be alkalinized until just before use.