Formulations with improved stability

1. A formulation comprising:

a compound having a structure:

or a pharmaceutically acceptable salt thereof; and

a lipophilic vehicle comprising at least one lipid excipient and at least one surfactant,

wherein the compound, or the pharmaceutically acceptable salt thereof, is soluble in the lipophilic vehicle,

wherein the lipophilic vehicle comprises at least two selected from the group consisting of PEG-200, PEG-300, PEG-400, a PEG castor oil, a lauroyl PEG glyceride, a stearoyl PEG glyceride, an oleoyl PEG glyceride, a caprylocapryl PEG glyceride, a PEG-20 glyceryl stearate, a glycerol oleate, a glycerol linoleate, a glycerol stearate, propylene glycol monocaprylate, polyglyceryl-3 dioleate, diethylene glycol monoethyl ether, d-alpha-tocopheryl polyethylene glycol 1000 succinate, polyoxyethylene (20) sorbitan monooleate, and polyoxyethylene (20) sorbitan monolaurate, and

wherein the formulation is suitable for oral administration.

2. The formulation of claim 1 , wherein a pH of the formulation is from about pH 4 to about pH 8.

3. The formulation of claim 1 , wherein an amount of the compound, or the pharmaceutically acceptable salt thereof, in the formulation decreases by less than about 2% after storage for 6 months at a temperature of 40° C. and a relative humidity of 75%.

4. The formulation of claim 1 , wherein the compound is a hydrochloride salt of:

5. The formulation of claim 1 , wherein the formulation is a semi-solid suspension.

6. The formulation of claim 1 , wherein the formulation is self-emulsifying.

7. The formulation of claim 6 , wherein the formulations has increased oral bioavailability in comparison to a formulation of the compound that is not self-emulsifying.

8. The formulation of claim 1 , wherein the lipophilic vehicle comprises polyoxyethylene (20) sorbitan monooleate, the PEG castor oil, and a phosphatidylcholine.

9. The formulation of claim 1 , wherein the lipophilic vehicle comprises the glycerol oleate, polyoxyethylene (20) sorbitan monooleate, the PEG castor oil, and a phosphatidylcholine.

10. The formulation of claim 8 , further comprising an antioxidant.

11. The formulation of claim 10 , wherein the antioxidant is butylated hydroxyanisole.

12. The formulation of claim 9 , further comprising an antioxidant.

13. The formulation of claim 12 , wherein the antioxidant is butylated hydroxyanisole.

14. The formulation of claim 8 , wherein the PEG castor oil is PEG-35 castor oil.

15. The formulation of claim 9 , wherein the PEG castor oil is PEG-35 castor oil.

16. The formulation of claim 10 , wherein the PEG castor oil is PEG-35 castor oil.

17. The formulation of claim 11 , wherein the PEG castor oil is PEG-35 castor oil.

18. The formulation of claim 12 , wherein the PEG castor oil is PEG-35 castor oil.

19. The formulation of claim 13 , wherein the PEG castor oil is PEG-35 castor oil.

20. The formulation of claim 1 , wherein the glycerol linoleate is at least one of glyceryl monolinoleate, glyceryl dilinoleate, and glyceryl trilinoleate.