Amitraz compositions

1. A composition which comprises a non-hydroxyl-group-containing solvent mixture comprising N,N-diethyl-m-toluamide and γ-hexylactone, optionally with dimethyl sulfoxide, eucalyptol and 1-methoxy-2-propyl acetate; and an effective amount of each of amitraz and 2-[2-(4-cyanophenyl)-1-[3-(trifluoromethyl)phenyl]ethylidene]-N-[4-(trifluoromethoxy)phenyl]-hydrazinecarboxamide (R-28153).

2. The composition according to claim 1 wherein the solvent mixture comprises about 2-30% w/v of N,N-diethyl-m-toluamide; 2-30% w/v of dimethyl sulfoxide; 2-30% w/v of eucalyptol; 2-40% w/v of γ-hexylactone, and 2-40% w/v of 1-methoxy-2-propyl acetate.

3. The composition according to claim 1 wherein the effective amount is about 10-30% w/v of amitraz and about 10-30% w/v of R-28153.

4. The composition according to claim 1 wherein the effective amount is about 3-9% w/v of amitraz and about 3-9% w/v of R-28153.

5. The composition according to claim 3 wherein the effective amount is about 13-20% w/v of amitraz and about 13-20% w/v of R-28153.

6. The composition according to claim 4 wherein the effective amount is about 5-7% w/v of amitraz and about 5-7% w/v of R-28153.

7. The composition according to claim 5 wherein the solvent mixture is about 5-25% w/v of N,N-diethyl-m-toluamide; 5-25% w/v of dimethyl sulfoxide; 5-25% w/v of eucalyptol; 10-30% w/v of γ-hexylactone; and 15-35% w/v of 1-methoxy-2-propyl acetate.

8. A method for the treatment and control of ectoparasiticidal infection or infestation in a homeothermic animal which comprises topically administering to said animal a composition, which comprises a non-hydroxyl-group-containing solvent mixture comprising N,N-diethyl-m-toluamide and γ-hexylactone, optionally with dimethyl sulfoxide, eucalyptol and 1-methoxy-2-propyl acetate; and an effective amount of each of amitraz and 2-[2-(4-cyanophenyl)-1-[3-(trifluoromethyl)phenyl]ethylidene]-N-[4-(trifluoromethoxy)phenyl]-hydrazinecarboxamide (R-28153).

9. The method according to claim 8 wherein said composition is administered as a spot-on, pour-on, dip, wash, gel, shampoo, spray, foam, or lotion.

10. The method according to claim 8 wherein said animal is selected from the group consisting of dogs; cats; swine, cattle; horses; and sheep.

11. The method according to claim 10 wherein said ectoparasiticidal infection or infestation is caused by fleas, ticks, lice, mites or flies.

12. The method according to claim 8 wherein said composition is administered as a spot-on.

13. The method according to claim 12 wherein said animal is a dog or cat.

14. The method according to claim 13 wherein said ectoparasiticidal infection or infestation is caused by fleas or ticks.

15. The method according to claim 8 wherein said composition is administered as a pour-on.

16. The method according to claim 15 wherein said animal is swine, sheep or cattle.

17. The method according to claim 14 wherein the effective amount of amitraz is about 13-20% w/v and R-28153 is about 13-20% w/v.

18. The method according to claim 16 wherein the effective amount of amitraz is about 3-9% w/v and R-28153 is about 3-9% w/v.

19. A process for the preparation of a composition according to claim 1 which comprises: admixing N,N-diethyl-m-toluamide and γ-hexylactone, optionally with eucalyptol, dimethyl sulfoxide and 1-methoxy-2-propyl acetate to form a solvent mixture; and treating said solvent mixture with amitraz and 2-[2-(4-cyanophenyl)-1-[3-(trifluoromethyl)phenyl]ethylidene]-N-[4-(trifluoromethoxy)phenyl]-hydrazinecarboxamide (R-28153) to form a homogeneous solution, optionally passing said solution through a solid dehydrating agent.

20. The process according to claim 19 wherein the solid dehydrating agent is 4 Å molecular sieves.