Application of the HPLC method for benzalkonium chloride determination in aerosol preparations.

Benzalkonium chloride (BAC) is a bacteriostatic agent used in the pharmaceutical industry as a preservative. BAC is a mixture of alkylbenzyldimethylammonium chlorides, the three most important of which being those with alkyl substituents C12, C14, C16 at the quaternary ammonium salt. The purpose of this study was to develop a method for determining benzalkonium chloride identity and content in aerosol preparations in which protein or steroid hormones are the active components. The high performance liquid chromatography (HPLC) method was used for this purpose. In the performed comparison of the influence of selected factors on the process of the separation of BAC homologues, a column with packing modified with cyan groups and mobile phase containing 0.075 M acetate buffer with acetonitrile (45:55), in an isocratic elution, was used for qualitative and quantitative determinations and for method validation. The developed method may be used for the assessment of the identity and content of BAC homologues in various pharmaceutical preparations. It is simple and it does not require particular sample preparation for the tests. It is characterized by good selectivity and high precision of the determinations.