Simultaneous determination of pramoxine HCl and benzalkonium chloride in wound care solutions by HPLC

A simple gradient reversed-phase high performance liquid chromatography (H PLC) method was developed for the simultaneous determination of total benzalkonium chloride (BAC) and pramoxine HCl in wound care solutions. Laboratory formulations were diluted 1 10 with water and injected into a HPLC system equipped with a Phenomenex, Luna CN column (100 angstrom, 5 mu m, 250 mm x 4.6 mm) in order for BAC and pramoxine to separate from other excipients and be detected by a UV detector (lambda = 262 nm) The mobile phase was 0 075 mM sodium acetate trihydrate buffer (pH = 5 0) using multi-ramp gradient elution with acetonitrile Quantitation was achieved by direct comparison of the peaks of BAC and pramoxine HCl of the sample to a reference standard of known concentrations A stress study with acid, base, peroxide. heat, and light indicated no interference from drug product or excipients The mean recovery results for both pramoxine and benzalkonium chloride at 100% level were 100 5 +/- 03%. 100.5 +/- 0.1% respectively (mean +/- SD, n = 6). In this report, the full experimental results from developing and validating this method are presented