Metolazone emulsion formulation

1. A parenteral metolazone oil-in-water emulsion formulation, comprising:

a) 0.1-10 mg/mL of metolazone or a pharmaceutically acceptable salt thereof;

b) 2-30% v/v of a lipid selected from the group consisting of soybean oil, safflower seed oil, olive oil, cottonseed oil, sunflower oil, sesame oil, peanut oil, corn oil, medium chain triglycerides, triacetin, propylene glycol diesters, monoglycerides, and a mixture of two or more thereof;

c) 0.1-2% w/v of an emulsifier selected from the group consisting of egg yolk phospholipids, soybean phospholipids, synthetic phosphatidyl cholines, purified phosphatidyl cholines and hydrogenated phosphatidyl choline, and mixtures of two or more thereof;

d) 1-4% w/v of a tonicity modifier selected from the group consisting of sodium chloride, sodium acetate, potassium chloride, mannitol, sucrose, lactose, fructose, maltose, dextrose, dextrose anhydrous, and glycerin; and,

e) 0.05-5% v/v of a co-emulsifier selected from the group consisting of poloxamers, polyoxyethylene stearates, sorbitan fatty acid esters, polysorbates, tocopherol PEG succinate, cholic acid, deoxycholic acid, oleic acid, and pharmaceutically acceptable salts thereof;

wherein:

benzyl alcohol is excluded,

the polydispersity index of the formulation is less than 0.2 measured on a dispersion of the formulation in 10 mM NaCl.

2. The formulation of claim 1 , wherein the average particle size of the formulation is from 70-180 +/−20 nm in particle size.

3. The formulation of claim 1 , further comprising:

g) 0.001-1% w/v of an antimicrobial agent.

4. The formulation of claim 3 , wherein the antimicrobial agent is selected from the group consisting of EDTA, sodium ascorbate, citric acid, and mixtures and salts thereof.

5. The formulation of claim 3 , wherein the antimicrobial agent is EDTA.

6. The formulation of claim 1 , wherein the formulation has a pH of 6.0-8.8.

7. The formulation of claim 1 , wherein the lipid is soybean oil.

8. The formulation of claim 1 , wherein the emulsifier is L-α-Lecithin.

9. The formulation of claim 1 , wherein the co-emulsifier is polysorbate 80.

10. The formulation of claim 1 , wherein the co-emulsifier is poloxamer 188.

11. The formulation of claim 1 , wherein the tonicity agent is glycerin.

12. The formulation of claim 1 , further comprising:

h) an antioxidant, present at about 0.01 to about 1.0% w/v.

13. The formulation of claim 12 , wherein the antioxidant is selected from the group consisting of sodium ascorbate, sodium citrate, cysteine hydrochloride, sodium bisulfate, sodium metabisulfite, sodium sulfite, ascorbyl palmitate, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), propyl gallate, tocopherol, and a pharmaceutically acceptable salt thereof.

14. The formulation of claim 12 , wherein the antioxidant is sodium ascorbate.

15. The formulation of claim 1 , wherein the formulation is contained in a sterile pre-filled syringe.

16. The formulation of claim 1 , wherein the particle size is obtained by high pressure homogenization or microfluidics.