On-plate spot test for identification and separation of benzalkonium chloride and cetrimide in drug samples: A mechanistic view

A mechanism showing different modes of interaction of benzalkonium chloride and cetrimide with the stationary and mobile phase has been proposed which leads to the separation of this surfactant mixture. Other combination of cationic surfactants was also separated from their binary mixture by the chromatographic system comprising of silica gel and combination of green solvents as mobile phase. The effect of presence of impurities on separation process was also examined and the limits of detection of the separated surfactants were calculated. The developed method was also successfully applied for the identification of cetrimide and benzalkonium chloride in pharmaceutical formulations.