Gatifloxacin eyedrops was prepared with benzalkonium as bacteriostat,NaCl as osmotic-pressure regulating agent and PVP as thickener:The content was determined with HPLC.
An alternate procedure is to soak the affected areas in an iced 0.13% water solution (1:750) of Zephiran chloride (benzalkonium chloride solution, NF).