Organic-phase biosensors for monitoring phenol and hydrogen peroxide in pharmaceutical antibacterial products.

Organic-phase biosensors open new opportunities for assays of challenging pharmaceutical products. Such opportunities are illustrated for the rapid determination of phenol and peroxide antiseptics in different anti-infective formulations. The tyrosinase and peroxidase enzyme electrodes offer reliable quantification of these antibacterial agents following sample dissolution in the organic solvent. The dynamic properties of these enzyme electrodes are exploited for rapid and reproducible flow-injection assays of the pharmaceutical products (relative standard deviation = 1.6-1.9%). Such developments should facilitate rapid quality control testing in the pharmaceutical industry and should be applicable to other therapeutic agents and products. Applicability to cosmetic products containing hydrogen peroxide is also demonstrated.