Hydrophobically modified chitosan compositions
Disclosed herein is a polymer composition comprising an effective amount of a hydrophobically-modified polymer having functional groups along the backbone occupied by a fatty acid anhydride moiety. The polymer composition has a potent hemostatic action by gelling blood upon contact, and is suitable for treating internal and external bleeds. As disclosed herein, the modified polymer can be generated without the use of toxic reagents that would require removal from the product. Further, compositions are shelf stable even in a flowable form. That is, the hydrophobic grafts are not lost under product storage conditions (e.g., room temperature storage).
1 . A polymer composition comprising an effective amount of a hydrophobically-modified chitosan, the hydrophobically-modified chitosan having hydrocarbon groups attached to the chitosan backbone through amide linkages, wherein the composition is formulated with a pH of about 5 or less and is in the form of a gel, film, powder, foam or putty,
wherein the hydrophobic groups comprise C1 to C4 hydrocarbon groups and a hydrocarbon greater than C6, and
wherein the C1 to C4 hydrocarbon groups are present at 20 mol % to 40 mol % with respect to amine groups of chitosan.
2 . The polymer composition of claim 1 , wherein the polymer composition is a gel.
3 . The polymer composition of claim 1 , wherein the polymer composition is a film.
4 . The polymer composition of claim 1 , wherein the polymer composition is a powder.
5 . The polymer composition of claim 1 , wherein the polymer composition is a foam.
6 . The polymer composition of claim 1 , wherein the polymer composition is a putty.
7 . The polymer composition of claim 1 , wherein the hydrophobically-modified chitosan has about 1% to about 10% of available amines substituted with the greater than C6 hydrocarbon group.
8 . The polymer composition of claim 7 , wherein the hydrophobically-modified chitosan has less than about 3% of available amines substituted with the greater than C6 hydrocarbon group.
9 . The polymer composition of claim 8 , wherein at least one hydrocarbon group is a linear C14, C16, or C18 hydrocarbon moiety.
10 . The polymer composition of claim 9 , wherein the chitosan is a medium molecular weight chitosan.
11 . The polymer composition of claim 1 , wherein the hydrophobically-modified chitosan has 2 or 3 different hydrocarbon groups conjugated along the chitosan backbone.
12 . The polymer composition of claim 11 , having a population of C6 to C12 hydrocarbon groups, and a population of C14 to C18 hydrocarbon groups.
13 . The polymer composition of claim 1 , wherein the composition is formulated in a dilute organic acid, the organic acid having a pKa of from about 2 to about 5.
14 . The polymer composition of claim 13 , wherein the organic acid is lactic acid, acetic acid, formic acid, or malic acid.
15 . The polymer composition of claim 13 , wherein the hydrophobically-modified chitosan is present at 0.1 to about 5% by weight.
16 . The polymer composition of claim 13 , wherein the organic acid is present in the composition from about 0.05M to 0.4M.
17 . The polymer composition of claim 1 , wherein the composition further comprises at least one synthetic polymer.
18 . The polymer composition of claim 17 , wherein the synthetic polymer is a polythene, polystyrene, polyacrylate, polyamide, polyester, polyurethane, polysulfide, or polycarbonate.
19 . The polymer composition of claim 17 , wherein the synthetic polymer is polyethylene glycol.
20 . The polymer composition of claim 1 , wherein the C1 to C4 hydrocarbon groups are present at 30 mol % to 40 mol % with respect to amine groups of chitosan.