Synergistic antimicrobial compositions containing poly (hexamethylammonium) chloride

#The present invention relates generally to antimicrobial compositions, and more particularly to new antimicrobial compositions comprising synergistic mixtures of Poly(hexamethylammonium) chloride ("Q6/6") and certain other biocides.

#The use of antimicrobial agents to eliminate or control the growth of various microorganisms is widely known. For example, it is known to use antimicrobial agents to control the growth of microorganisms in a variety of industrial processes, including those relating to the paint, pulp, paper, oil, rubber and tobacco industries; to use antimicrobials in commercial settings, particularly to disinfect contaminated surfaces; and to include antimicrobial agents in a wide variety of houseliold goods such as foods, cosmetics and toiletries.

#To accommodate such needs, a variety of antimicrobial agents are known. However, despite the many commercially available antimicrobials, no single agent is entirely suitable for every application. Problems with efficacy, safety, environmental acceptability and cost make certain antimicrobials more or less suitable for a particular application.

#A synergistic composition according to the present invention can be made by dissolving Q6/6 and poly(iminoimidocarbonyliminoimidocarbonyliminohexamethylene hydrochloride ("PHMB") together in water at room temperature. Alternatively, the active ingredients can be added to the media to be treated from separate solutions to achieve the same synergistic effect. A wide range of ratios of the two active ingredients can be used, depending on the microorganism to be controlled. For example, to control the growth of Scenedesmus obliquus, the ratio of Q6/6 to PHMB may be as low as 1:2. To control growth of Aspergillus niger, the ratio of Q6/6 to PHMB may be 4:1. Preferred ratios of Q6/6 to PHMB for use with other microorgaisms typically lie in the range of about 31:1 to about 2:1.

#Further synergistic compositions according to the present invention are made by dissolving Q6/6 and/or dodecylguanidine hydrochloride ("DGH") and poly[oxyethylene (dimethylimino) ethylene-(dimethylimino) ethylene dichloride] ("PDED"). Again, a wide range of ratios of two active ingredients can be used, depending on several factors including the microorganism to be controlled. For example, preferred ratios of Q6/6 to the other antimicrobial is generally are about 4:1 to about 8:1 for DGH and about 8:1 to about 65:1 for PDED.

#The antimicrobial compositions described above can be seen to exhibit synergistic activity with respect to a variety of common microorganisms. However, the examples disclosed herein should not be considered to disclose all possible microorganisms which may be controlled by the synergistic combinations, nor should the identified ranges be viewed as limiting in nature. All synergistic antimicrobial combinations of the identified ingredients are intended to be within the scope of the present invention, and all antimicrobial uses thereof are intended to be claimed.