Long-acting injectable moxidectin formulations and novel moxidectin crystal forms
This invention provides for novel antiparasitic and pesticidal forms of moxidectin, including a long-acting polymeric implant. The resulting compounds may be used in veterinary compositions which are used in treating, controlling and preventing of endo- and ectoparasite infections in animals.
1. A long-acting polymeric implant for non-human animals comprising PLGA and amorphous moxidectin.
2. The implant of claim 1 wherein the PLGA has an L:G ratio of about 50-75% to about 25-50% L:G.
3. The implant of claim wherein the L:G ratio is 75:25.
4. The implant of claim 3 which is active against endoparasites for a period of greater than 3 months.
5. The implant of claim 4 which is active against endoparasites for a period of greater than 4 months.
6. The implant of claim 5 which is active against endoparasites for a period of greater than 6 months.
7. The implant of claim 1 wherein the endoparasites are heartworms.
8. The implant of claim 1 wherein the animals are cats or dogs or cattle.
9. A method of producing the implant of claim 1 comprising the steps of:
a) producing a solution of moxidectin and PLGA in a suitable solvent;
b) adding from 0-1% (w/w) antioxidant;
c) removing the solvent using a suitable drying means;
d) subjecting the dried material of step c to extrusion at a suitable temperature to produce polymer strands;
e) cutting or otherwise reducing the size of the polymer strands, thereby producing the implant.
10. The method of claim 9 wherein the solvent is methylene chloride and the drying means is a Buchi spray drier.
11. The method of claim 9 wherein the extrusion is performed at a temperature suitable for retaining the moxidectin in an amorphous state.
12. The method of claim 11 wherein the extrusion is not performed above 180° C.
13. The method of claim 12 wherein the extrusion is performed at between about 110° C. and about 180° C.
14. The method of claim 13 wherein the extrusion is performed at about 118° C.