Simple High Performance Liquid Chromatography Method for Determination of Benzalkonium Chloride Homologues in Nasal Preparations

SUMMARY. A High-Performance Liquid Chromatography method was developed for quantification of benzalkonium chloride (BAC) and separation of three major homologues, in nasal preparations. Chro-matography separation was carried out on a CLC-cyano column, using 0.075M acetate buffer with ace-tonitrile (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%, re-spectively. 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