Branched polymeric biguanide compounds and their uses

Abstract

Biocidal branched polymeric biguanide compounds are made by polycondensation of sodium dicyanamide and a Afunctional primary amine and/or a tetrafunctional primary amine and optionally with a difunctional primary amine. The branched polymeric biguanide compounds have 2-dimensional conformation that provides better coverage over the surfaces of microorganisms and enhances efficacy as biocides as compared to most commercially available linear (one-dimensional) polymeric biguanide compounds. The bulkier 2-dimensional conformation of this invention limits the uptake, accumulation and release of these branched polymers to and from contact lenses. Therefore, these branched biguanide polymers can reduce the cytotoxicity, enhance compatibility and suitable for ophthalmic use. The highly branched polymers can be prepared with minimum or no difunctional primary amines. The lightly branched polymers can be prepared with of a minimum ratio of trifunctional plus multifunctional primary amines to difunctional primary amines.