Patent ID: 7812163

Claim:
A method for inhibiting hatching of an ectoparasite egg comprising exposing the ectoparasite egg to a topical composition comprising at least one metal chelating agent wherein the at least one metal chelating agent is a compound of formula (Ia): wherein X is a covalent bond, CH 2 —Z—CH 2 or —Z— wherein R 1 and R 1′ are independently selected from hydrogen, or C 1-3 alkyl wherein at least one of R 2 , R 2′ −, R 3 , R 3′ −, R 4 and R 4′ − is a methyl group and the remaining R 2 , R 2′ , R 3 , R 3′ , R 4 and R 4′ are independently selected from hydrogen or C 1-3 alkyl Z is selected from a covalent bond, —NH—, —O—, —S—, —C(O)— and —C(S)—; or a pharmaceutically, veterinary or agriculturally acceptable salt thereof.