Simple high performance liquid chromatography method for determination of benzalkonium chloride homologues in nasal preparations

A High-Performance Liquid Chromatography method was developed for quantification of benzalkonium chloride (BAC) and separation of three major homologues, in nasal preparations. Chromatography separation was carried out on a CLC-cyano column, using 0.075M acetate buffer with acetonitrile (45:55, v/v) pH = 5.0, as mobile phase, in an isocratic elution. The total run time was 20 min at a flow rate of 1.0 mL/min. The retention times were of 10.0, 12.8 and 16.1 min, respectively, for homologs C12 , C14 and C16 of benzalkonium chloride. About precision, the method presented excellent repeatability and satisfactory precision intermediate, and the coefficients of variation found were 1.73 and 4.51%, respectively. The accuracy values were ranging from 100.86 to 110.99%. The lower limits of quantification and detection were 5 μg/mL and 2.5 μg/mL, respectively. Two out of seven analyzed lots contained less BAC than allowed. Colegio de Farmacéuticos de la Provincia de Buenos Aires