| abstract |
The present invention is directed to an ophthalmically safe disinfecting solution for contact lenses comprising a bis(biguanide) having formula (I) wherein R?1 and R4¿ are independently selected from the group consisting of branched or unbranched alkyl having 4-12 carbon atoms, ether or thioether radical having 4-12 carbon atoms, or cycloalkyl or cycloalkyl-alkyl radical having 5-12 carbon atoms; R?2 and R3¿ are independently selected from the group consisting of hydrogen, alkyl having 1-12 carbon atoms, alkoxyalkyl having 1-12 carbon atoms, or cycloalkyl or cycloalkyl-alkyl having 5-12 carbon atoms; R?6 and R7¿ are independently selected from the group consisting of hydrogen and alkyl radical having 1-6 carbon atoms, and A in the above formula is selected from the divalent radical having 4-16 carbon atoms consisting of a divalent alkyl, alkyloxyalkyl, alkylsulfide, or a polymethylene interrupted with a cyclic divalent radical. In one embodiment of the present invention, such biguanides may be combined with a polymeric biguanide for complementary or synergistic biocidal efficacy. The invention is also directed to an improved method of disinfecting a contact lens. |