Benzalkonium bromide solution chloride

Other quaternary ammonium germicides, ben-zethonium chloride and benzalkonium bromide, have been used in several ophthalmic solutions. While these have the advantage of not being a chemical mixture, they do not possess the bactericidal effectiveness of benzalkonium chloride and are subject to the same incompatibility limitations. In addition, the maximum concentration for benzethonium chloride is 0.01%. Several new products that form gels in the eye, like Timolol Gel Forming Solution and Timoptic-XE, employ another quaternary preservative, BDAB, in the formulation. 

Benzalkonium chloride at concentrations greater than 0.005 mg/ml causes histamine release from mast cells in vitro. At a concentration of 0.03 mg/ml an excess of 90% of the histamine content is released (5). This is in the range of the minimum concentration of benzalkonium chloride recommended as a disinfectant (0.025 mg/ml). Inhalation of benzalkonium chloride nebulizer solution causes concentration-related falls in FEVi in patients with asthma (6). Benzalkonium chloride 0.3 mg also causes a temporary increase in airway reactivity to histamine. This amount of benzalkonium chloride is similar to that in a 2.5 mg dose from a multidose vial of salbutamol (7). Ipratropium containing benzalkonium chloride 0.25 mg/ml causes bronchoconstriction in a proportion of patients with asthma. BronchodUatation is seen when 2 ml (0.5 mg) of preservative-free ipratropium bromide solution is inhaled (8). Benzalkonium chloride 0.1 mg/ml does not alter the bronchodUator effect of salbutamol. The difference between salbutamol and ipratropium may be the lower concentration of benzalkonium chloride in the salbutamol solution (0.1 versus 0.25 mg/ml) and the greater potency and more rapid onset of the bronchodilator response to salbutamol (9). Individual case reports suggest that... 

Electrospray MS. Analysis of methanol solutions in the positive ion mode gives molecular ions of distearyldimethylammonium chloride. Strong ions are seen for the Cj / Cis, Cis/Ci6, and Cifi/Cig homologs, as well as some minor components (15,120). It must be noted that the response factors differ sharply for similar compounds. For example, the response factor for hexadecyltrimethylammonium bromide is only 45% of that for dode-cyltrimethylammonium bromide (117). The same observations on calibration with deuter-ated analogs and fragments for MS-MS analysis made above for FAB also apply to electrospray (117). Electrospray MS was demonstrated for detection of benzalkonium chloride on human skin, using a triple quadrupole instmment in multiple reaction monitoring mode (121). 

---