Determination of benzalkonium chloride by reversed-phase high-pressure liquid chromatography.

A new, specific, and useful approach for the analysis of benzalkonium chloride is presented. Reversed-phase high-pressure liquid chromatography is used to determine benzalkonium chloride in an ophthalmic system at the presevative level of 0.004%. Since the method separates each homolog, it can be extended to determine the homolog composition. These determinations can be made with an analysis time of 13 min/sample.