A stability-indicating HPLC method for the determination of benzalkonium chloride in 0.5% tramadol ophthalmic solution

Summary A high-performance liquid chromatographic procedure employing ultraviolet detection for the analysis of benzalkonium chloride in 0.5% Tramadol ophthalmic solution is reported. The method requires minimal sample pretreatment and is sensitive, accurate, and reproducible. The peak area versus BAK concentration is linear over the range of 50–150% of its label claim of 0.05 mg/mL. The mean absolute recovery of BAK using the described method is 100.2±1.2%, (mean ±SD, n=10). A stress study with heat, acid, base and UV radiation indicates that the method is stabilityindicating with no interference from drug or degradation products.