Amphoteric surfactant solution for cleaning or preserving soft contact lenses

Abstract From the Canadian patent

4-15760/+/CGC 1180, Amphoteric surfactant solution for cleaning or preserving soft contact lenses, Abstract of the Disclosure The instant invention relates to an aqueous self-preserving soft contact lens cleaning or preserving solution comprising as its only, preservative agent, an effective surfactant and solution preserving amount of a water-soluble amphoteric surfactant of the formula I (I), wherein R is alkyl, alkenyl or alkanedienyl of 6 to 18 carbon atoms each of which are unsubstituted or substituted by halo hydroxy or, amino; A is -O-, -S-, -C(O)O- or -C(O)NR'- where R' is hydrogen or lower alkyl; R1 is alkylene of 2 to 6 carbon atoms which is unsubstituted or substituted by …