Pharmaceutical suspensions containing drug particles, devices for their administration, and methods of their use

1. A pharmaceutical composition comprising a suspension comprising (i) an oil, and (ii) from about 35% to 70% (w/w) solid drug particles comprising levodopa and/or carbidopa, wherein the pharmaceutical composition is physically stable and wherein said pharmaceutical composition is a non-pourable, plastically deformable paste.

2. The pharmaceutical composition of claim 1 , wherein after centrifugation for 1 hour at an acceleration of about 5,000 G at 25±3° C. the concentrations of drug in the layer containing the top 20 volume % and the layer containing the bottom 20 volume % of the composition differ by less than 4%.

3. The pharmaceutical composition of claim 2 , wherein said suspension has a dynamic viscosity of at least 10,000 cP at 37° C.

4. The pharmaceutical composition of claim 1 , wherein said suspension comprises less than or equal to about 30% (w/w) of said oil.

5. The pharmaceutical composition of claim 4 , wherein said suspension comprises greater than or equal to about 19% (w/w) of said oil.

6. The pharmaceutical composition of claim 3 , wherein said suspension comprises water and a surfactant.

7. The pharmaceutical composition of claim 1 , wherein said solid drug particles comprise carbidopa, and wherein said pharmaceutical composition comprises less than 4 μg of hydrazine per mg of carbidopa after 12 month storage at 5±3° C., or less than 1 μg of hydrazine per mg of carbidopa after 3 month storage at 5±3° C.

8. The pharmaceutical composition of claim 1 , said pharmaceutical composition comprising a suspension comprising (i) from about 35% to 70% (w/w) solid drug particles comprising levodopa and/or carbidopa, (ii) from 19% to 30% (w/w) of one or more water-immiscible compounds comprising an oil, (iii) from 2% to 16% (w/w) water, and (iv) from 1% to 8% (w/w) surfactant, wherein the pharmaceutical composition is suitable for continuous or frequent intermittent intra-oral delivery.

9. The pharmaceutical composition of claim 8 , wherein said suspension has a dynamic viscosity of at least 10,000 cP at 37° C.

10. The pharmaceutical composition of claim 9 , wherein said suspension has a dynamic viscosity of at least 100,000 cP at 37° C.

11. The pharmaceutical composition of claim 9 , wherein after centrifugation for 1 hour at an acceleration of about 5,000 G at 25±3° C. the concentrations of drug in the layer containing the top 20 volume % and the layer containing the bottom 20 volume % of the composition differ by less than 4%.

12. The pharmaceutical composition of claim 9 , wherein the shelf life of said pharmaceutical composition is 6 months or longer at 5±3° C. and said pharmaceutical composition does not substantially cream or sediment when stored for 6 months at 5±3° C.

13. The pharmaceutical composition of claim 9 , wherein said suspension is a non-pourable, plastically deformable paste, and retains its shape at ambient temperature following extrusion through an orifice.

14. The pharmaceutical composition of claim 9 , wherein said pharmaceutical composition comprises an emulsion.

15. The pharmaceutical composition of claim 9 , wherein the suspension comprises greater than 50% (w/w) solid drug particles.

16. The pharmaceutical composition of claim 9 , wherein the D 50 of the solid drug particles is less than or equal to 25 μm when measured by light scattering with the particles dispersed in a non-solvent.

17. The pharmaceutical composition of claim 16 , wherein the D 50 of the solid drug particles is greater than or equal to 1 μm when measured by light scattering with the particles dispersed in a non-solvent.

18. The pharmaceutical composition of claim 9 , wherein said suspension comprises less than or equal to about 12% (w/w) water.

19. The pharmaceutical composition of claim 18 , wherein said suspension comprises 8±2% (w/w) water.

20. The pharmaceutical composition of claim 9 , wherein said oil comprises a saturated fatty acid triglyceride, an unsaturated fatty acid triglyceride, a mixed saturated and unsaturated fatty acid triglyceride, a medium-chain fatty acid triglyceride, canola oil, coconut oil, palm oil, olive oil, soybean oil, sesame oil, corn oil, or mineral oil.

21. The pharmaceutical composition of claim 20 , wherein said oil comprises a medium-chain fatty acid triglyceride.

22. The pharmaceutical composition of claim 9 , wherein said pharmaceutical composition comprises a non-ionic surfactant.

23. The pharmaceutical composition of claim 22 , wherein said non-ionic surfactant comprises a polyglycolized glyceride, an alkyl saccharide, an ester saccharide, or a polysorbate surfactant.

24. The pharmaceutical composition of claim 22 , wherein said non-ionic surfactant comprises a poloxamer.

25. The pharmaceutical composition of claim 22 , wherein said suspension comprises about 5±2% (w/w) of said surfactant.

26. The pharmaceutical composition of claim 9 , wherein the pH of the composition measured by inserting a glass walled pH electrode into the formulation is less than pH 5 and remains less than pH 5 after 3 months storage at 25° C.

27. A pharmaceutical composition comprising a suspension comprising (i) from about 35% to 70% (w/w) solid drug particles comprising levodopa and/or carbidopa, (ii) from 19% to 30% (w/w) of one or more water-immiscible compounds comprising an oil, (iii) from 2% to 16% (w/w) water, (iv) from 1% to 8% (w/w) surfactant, and (v) benzoic acid or a benzoate salt wherein the pharmaceutical composition is physically stable, wherein the pharmaceutical composition is suitable for continuous or frequent intermittent intra-oral delivery, and wherein said suspension has a dynamic viscosity of at least 10,000 cP at 37° C.

28. A pharmaceutical composition comprising a suspension comprising (i) from about 35% to 70% (w/w) solid drug particles comprising levodopa and/or carbidopa, (ii) from 19% to 30% (w/w) of one or more water-immiscible compounds comprising an oil, (iii) from 2% to 16% (w/w) water, (iv) from 1% to 8% (w/w) surfactant, and (v) EDTA or its salt or salts, wherein the combined concentrations of EDTA and its salt or salts is between 0.05 weight % and 0.25 weight %, wherein the pharmaceutical composition is physically stable, wherein the pharmaceutical composition is suitable for continuous or frequent intermittent intra-oral delivery, and wherein said suspension has a dynamic viscosity of at least 10,000 cP at 37° C.

29. The pharmaceutical composition of claim 1 , wherein said pharmaceutical composition comprises: (i) from about 50% to about 75% (w/w) of said solid drug particles; (ii) 8±2% (w/w) water, (iii) 24±2% (w/w) of said oil, wherein said oil is a medium-chain fatty acid triglyceride; and (iv) 5±2% (w/w) of a surfactant that is a poloxamer.