Determination of benzalkonium chloride in eye care products by high-performance liquid chromatography and solid-phase extraction or on-line column switching.
Benzalkonium chloride (BAK) is a mixture of alkylbenzyldimethylammonium chlorides, which is commonly used as a bacteriostat. In this work, the three major homologues of BAK are quantitated in the over-the-counter eye care products Murine and Murine Plus using high-performance liquid chromatography (HPLC). The analytes are separated from various product excipients and concentrated by either solid-phase extraction onto Sep-Pak C18 cartridges or by an on-line column-switching technique using 1-cm reversed-phase precolumns. Absolute recoveries of BAK homologues by the solid-phase extraction technique ranged from 97.2 to 98.7% for standards and from 98.0 to 98.4% for samples. Absolute recovery of the BAK homologues by the column-switching technique was 101.3% for standards and ranged from 99.9 to 103.7% for samples. Relative recoveries were quantitative by both techniques. Assay precision (R.S.D. values) were +/- 2.2% to +/- 2.6% and +/- 0.4% to +/- 0.8% by solid-phase extraction and column-switching techniques, respectively. The method provides advantages of high sample throughput, excellent column life and automation.
Elrod
L
L
PPD Physical Analytical Chemistry Department, Abbott Laboratories, North Chicago, IL 60064.
Golich
T G
TG
Morley
J A
JA
D001548:Benzalkonium Compounds / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D009883:Ophthalmic Solutions / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
D001548:Benzalkonium Compounds; D009883:Ophthalmic Solutions