[Local anesthetics: simultaneous HPLC determination of lidocaine (Xylocaine) and bupivacaine (Marcaine) in human serum].

In order to monitor loco-regional anaesthesia in the upper limbs with a combination of two anaesthetics, the authors participated in a clinical pharmacology study. They describe a method of simultaneous assay of bupivacaine and lignocaine by direct phase HPLC. In particular, the use of heptane sulfonic acid (counter-ion) in the mobile phase allows the elution of the local anaesthetics to be controlled. The criteria of reliability studied enable this technique to be considered for routine use.