Development and validation of chromatographic methods (HPLC and GC) for the determination of the active components (benzocaine, tyrothricin and menthol) of a pharmaceutical preparation.

Methods are reported for the determination of tyrothricin and benzocaine by HPLC and menthol by GC in the analysis of throat lozenges (tablets) containing all three compounds. After optimization of the variables involved in both HPLC and GC the methods have been characterized and validated according to the guidelines of the Spanish Pharmacopoeia, and applied to both the monitoring of the manufacturing process and the quality control of the final product.