Batch variability of bacitracin: HPLC versus MEKC.

10 lots of bacitracin collected from the European market were studied applying the European Pharmacopoeia HPLC method, and the results were compared to the findings of an orthogonal micellar electrokinetic chromatographic method. The latter method exhibited a far higher selectivity, resulting in a baseline separation of all bacitracin components, which could not be achieved with HPLC. Considering the contents of bacitracin A, B1, and B3, the lots could be organised into 2 groups. Due to high amounts of bacitracin B1 and B3, one lot did not fit into either group. All lots met the requirements of the European Pharmacopoeia.