Two Novel Methods for the Determination of Benzalkonium Chloride in Bandages by Resonance Light Scattering Technology

Abstract

In this study, two novel resonance light scattering (RLS) methods were developed for the determination of benzalkonium chloride. These methods were based on the formation of inorganic anionic-surfactant aggregates in a Clark-Lubs medium, which increases the resonance light scattering intensity of the reaction system and were also predominantly divided into sodium tungstate-benzalkonium chloride (method A) or phosphomolybdate-benzalkonium chloride (method B). The detection is performed both at 285 nm. Under the established conditions, the limits of quantification ranged from 0.10 mg L –1 to 1.00 mg L –1 with the R values of 0.9994 and from 0.20 mg · L –1 to 3.20 mg · L –1 with the R values of 0.9991, with good precision and accuracy both for method A and method B. The limits of detection were 0.029 mg · L –1 for method A and 0.013 mg · L –1 for method B. These two methods were successfully applied for the assay of benzalkonium chloride for the first time. All validation parameters were in agreement with the International Conference on Harmonization of Requirements for Registration Pharmaceuticals for Human Use (ICH) guidelines. Compared to the classical spectrophotometric method, these two methods take advantages of rapidity, high efficiency and good selectivity.