PROTEINS AND PROTEIN CONJUGATES WITH INCREASED HYDROPHOBICITY
Examples may include a method of making a protein-PEG conjugate salt with increased hydrophobicity. The method may include providing an aqueous protein solution. This aqueous protein solution may include a protein and a pH buffer. The method may also include reacting a polyethylene glycol with the protein to form a protein-PEG conjugate. The method may further include protonating an amino group on the protein-PEG conjugate with a hydrophobic organic acid in an organic phase. The protonation may form the protein-PEG conjugate salt having a hydrophobic anion that increases the hydrophobicity-PEG conjugate salt.
1 . A composition comprising:
a biodegradable polymer;
an organic solvent; and
a protein mixture selected from the group consisting of a protein-polyethylene glycol conjugate and a hydrophobic anion of an organic acid, a protein and the hydrophobic anion of the organic acid, and combinations thereof, wherein the composition is presented as a solution or a suspension.
2 . The composition of claim 1 , wherein the composition is presented as the solution.
3 . The composition of claim 1 , wherein the composition is presented as the suspension.
4 . The composition of claim 1 , wherein the protein of the protein-polyethylene glycol conjugate or the protein is selected from the group consisting of human growth hormone, glucagon-like peptide-1, insulin, parathyroid hormone, a fragment of parathyroid hormone, enfuvirtide, and octreotide.
5 . The composition of claim 1 , wherein the organic acid comprises pamoic acid, docusate hydrogen, furoic acid, or mixtures thereof.
6 . The composition of claim 1 , wherein:
the protein mixture comprises the protein and the hydrophobic anion of the organic acid, and
the hydrophobic anion of the organic acid comprises a fatty acid anion, a phospholipid anion, a polystyrene sulfonate anion, or mixtures thereof.
7 . The composition of claim 1 , wherein the organic solvent comprises N-methyl pyrrolidone, dimethyl sulfoxide, propylene glycol, ethyl benzoate, benzyl benzoate, triacetin, PEG 400, or mixtures thereof.
8 . The composition of claim 1 , wherein the biodegradable polymer is selected from the group consisting of a polylactide; a polyglycolide; a poly(d,l-lactide-co-glycolide); a polycaprolactone; a polyorthoester; a copolymer of a polyester and a polyether; and a copolymer of polylactide and polyethylene glycol.
9 . The composition of claim 1 , wherein the biodegradable polymer comprises poly(d,l-lactide-co-glycolide).
10 . The composition of claim 1 , wherein the biodegradable polymer has a molecular weight from 24,000 Da to 38,000 Da.
11 . The composition of claim 1 , wherein the biodegradable polymer comprises about 50% or less of lactide and about 50% or more of glycolide.
12 . A method of making a solution or suspension of a biodegradable polymer and a protein-PEG conjugate salt, the method comprising:
providing a protein-PEG conjugate, wherein the protein-PEG conjugate is free of the protein-PEG conjugate salt;
mixing the biodegradable polymer, the protein-PEG conjugate, a hydrophobic organic acid, and an organic solvent in a mixture;
forming the protein-PEG conjugate salt comprising the protein-PEG conjugate and an anion of the hydrophobic organic acid;
agitating the mixture to form the solution or the suspension.
13 . The method of claim 12 , wherein the organic solvent comprises N-methyl pyrrolidone, dimethyl sulfoxide, propylene glycol, ethyl benzoate, benzyl benzoate, triacetin, PEG 400, or mixtures thereof.
14 . The method of claim 12 , wherein:
the protein-PEG conjugate is a first protein-PEG conjugate,
the protein-PEG conjugate comprises a glucagon-like peptide-1-PEG conjugate,
mixing further comprises mixing a second protein-PEG conjugate with the biodegradable polymer, the protein-PEG conjugate, the hydrophobic organic acid, and the organic solvent in the mixture, and
the second protein-PEG conjugate comprises an insulin-PEG conjugate.
15 . A method of making a solution or suspension of a biodegradable polymer and a protein-PEG conjugate salt, the method comprising:
dissolving the biodegradable polymer in an organic solvent to form a mixture;
adding a protein-PEG conjugate and a hydrophobic organic acid to the mixture;
protonating an amino group on the protein-PEG conjugate with the hydrophobic organic acid, wherein protonation forms the protein-PEG conjugate salt having a hydrophobic anion;
agitating the mixture to form the solution or the suspension.
16 . The method of claim 15 , wherein the method does not comprise dissolving the protein-PEG conjugate salt in the organic solvent.
17 . The method of claim 15 , wherein the protein-PEG conjugate comprises a protein selected from the group consisting of human growth hormone, glucagon-like peptide-1, insulin, parathyroid hormone, a fragment of parathyroid hormone, enfuvirtide, and octreotide.
18 . The method of claim 15 , wherein the hydrophobic organic acid comprises pamoic acid, docusate hydrogen, furoic acid, or mixtures thereof.
19 . The method of claim 15 , wherein the organic solvent comprises N-methyl pyrrolidone, dimethyl sulfoxide, propylene glycol, ethyl benzoate, benzyl benzoate, triacetin, PEG 400, or mixtures thereof.
20 . The method of claim 15 , wherein the protein-PEG conjugate comprises:
an amide bond, an ester bond, or a disulfide bond between a polyethylene glycol and a protein, or
a thiol-reactive polyethylene glycol attached to a cysteine residue of the protein.