Sustained formulation for prevention or treatment of autoimmune disease containing naltrexone and method using the same

1. A sustained formulation, comprising microparticles comprising naltrexone or pharmaceutically acceptable salts thereof, and biodegradable polymers, wherein the end of the biodegradable polymer is capped or uncapped and a median particle size (D50) of the microparticles is 25 μm to 100 μm.

2. The formulation of claim 1 , wherein the biodegradable polymer comprises one or more selected from the group consisting of polylactide, polylactic acid, polylactide-co-glycolide, polylactic-co-glycolic acid, polyphosphazine, polyiminocarbonate, polyphosphoester, polyanhydride, polyorthoester, polycaprolactone, polyhydroxyvalate, polyhydroxybutyrate, and polyamino acids.

3. The formulation of claim 2 , wherein the molar ratio of glycolide to lactide in the polylactide-co-glycolide is 50:50 to 90:10.

4. The formulation of claim 2 , wherein the biodegradable polymer comprises one or more of polylactide and polylactide-co-glycolide.

5. The formulation of claim 2 , wherein the biodegradable polymer comprises one or more polylactide and one or more of polylactide-co-glycolide.

6. The formulation of claim 5 , wherein the weight ratio of polylactide and polylactide-co-glycolide is 1:10 to 10:1.

7. The formulation of claim 5 , wherein the weight ratio of polylactide and polylactide-co-glycolide is 1:1 to 2:1.

8. The formulation of claim 2 , wherein the biodegradable polymer comprises two or more of polylactide-co-glycolide.

9. The formulation of claim 8 , wherein the two or more polylactide-co-glycolides are polylactide-co-glycolides in a weight ratio of 1:10 to 10:1.

10. The formulation of claim 9 , wherein the two or more of polylactide-co-glycolides are polylactide-co-glycolides in a weight ratio of 1:1 to 2:1.

11. The formulation of claim 2 , wherein an intrinsic viscosity (IV) of the polylactide is 0.1 dl/g to 0.5 dl/g.

12. The formulation of claim 2 , wherein an intrinsic viscosity of the polylactide-co-glycolide is 0.1 dl/g to 1.5 dl/g.

13. The formulation of claim 4 , wherein an intrinsic viscosity of the polylactide is 0.1 dl/g to 0.5 dl/g.

14. The formulation of claim 4 , wherein an intrinsic viscosity of the polylactide-co-glycolide is 0.1 dl/g to 1.0 dl/g.

15. The formulation of claim 1 , wherein the residual amount of the solvent in the microsphere is 1000 ppm or less.

16. The formulation of claim 15 , wherein the residual amount of the solvent in the microsphere is 800 ppm or less.

17. The formulation of claim 15 , wherein the solvent is dichloromethane.

18. The formulation of claim 1 , wherein the biodegradable polymer is stirred with 200 to 400 rpm at 100° C. to 20° C. for 30 minutes to 2 hours, with 200 to 400 rpm at 25° C. to 35° C. for 30 minutes to 2 hours, and with 200 to 400 rpm at 35° C. to 45° C. for 30 minutes to 4 hours to remove the solvent.

19. The formulation of claim 1 , wherein the microparticle comprises biodegradable polymers and naltrexone or a pharmaceutically acceptable salt thereof in a weight ratio of 1:1 to 10:1.

20. The formulation of claim 1 , wherein naltrexone or a pharmaceutically acceptable salt thereof is homogenously dispersed in the microparticles.

21. The formulation of claim 1 , wherein the formulation is a parenteral formulation.

22. The formulation of claim 1 , wherein the formulation is an injection for subcutaneous administration or intramuscular administration.

23. The formulation of claim 1 , wherein the formulation comprises 0.1 mg to 1 g of naltrexone or a pharmaceutically acceptable salt thereof per unit dosage form.

24. The formulation of claim 1 , wherein the formulation is administered once a day to once a year.

25. The formulation of claim 24 , wherein the formulation is administered once every 1 week to 2 months.

26. The formulation of claim 1 , wherein the formulation is for administration at a dose of 0.1 mg/kg body weight to 1 g/kg body weight.