Wound dressing materials
A wound dressing material comprising: a wound dressing carrier, N-acetyl cysteine or a salt or derivative thereof, and a stabilized ascorbate. Suitably, the stabilized ascorbate comprises an ascorbate-2-polyphosphate. Also provided are wound dressings comprising the materials, methods of treatment with the materials, and methods of making the materials.
1. A method of making a wound dressing, the method comprising the steps of:
forming an aqueous dispersion, the aqueous dispersion comprising a bioabsorbable carrier material, N-acetyl cysteine or a salt thereof, a stabilized ascorbate, and an aqueous solvent, wherein a weight ratio of N-acetyl cysteine or a salt thereof to the stabilized ascorbate is from about 1:4 to about 4:1; and
freeze-drying or solvent-drying the aqueous dispersion to produce an active layer; wherein
the wound dressing comprises the active layer;
the active layer comprises a wound-facing side, the bioabsorbable carrier material, the N-acetyl cysteine or a salt thereof, and the stabilized ascorbate, where a weight ratio of N-acetyl cysteine or a salt thereof to the stabilized ascorbate is from about 1:4 to about 4:1 in the active layer; and
the stabilized ascorbate comprises a member selected from the group consisting of ascorbate 2-phosphate or polyphosphate compounds, trisodium L-ascorbyl-2-monophosphate, 2-phospho-L-ascorbic acid trisodium salt, magnesium ascorbyl phosphate (MAP), L-ascorbic acid mono(dihydrogen phosphate) magnesium salt, magnesium L-ascorbic acid-2-phosphate, trisodium L-ascorbyl-2-polyphosphate, and a combination of any two or more thereof.
2. The method of claim 1 , wherein the bioabsorbable carrier material is adapted to provide sustainable release of N-acetyl cysteine or a salt thereof and the stabilized ascorbate.
3. The method of claim 1 , wherein the active layer is in the form of a sponge.
4. The method of claim 1 , wherein the carrier material comprises oxidized cellulose.
5. The method of claim 1 , wherein the carrier material comprises collagen, chitosan, or both.
6. The method of claim 1 , wherein the carrier material comprises oxidized cellulose and one or both of collagen and chitosan.
7. The method of claim 1 , wherein the carrier material comprises oxidized regenerated cellulose.
8. The method of claim 1 , wherein the carrier material comprises oxidized regenerated cellulose and one or both of collagen and chitosan.
9. The method of claim 1 , wherein the stabilized ascorbate comprises ascorbate-2-tripho sphate.
10. The method of claim 1 , wherein the active layer comprises from about 1 wt.% to about 10 wt.% of the N-acetyl cysteine or a salt thereof, and from about 1 wt.% to about 10 wt.% of the stabilized ascorbate.
11. The method of claim 1 , wherein the aqueous dispersion comprises a solids concentration from about 0.5 wt.% to about 3 wt.%.
12. The method of claim 1 , wherein the aqueous dispersion comprises about 0.0002 wt.% to about 1 wt.% of the N-acetyl cysteine or a salt thereof.
13. The method of claim 1 , wherein the aqueous dispersion comprises about 0.03 wt.% to about 0.4 wt.% of the N-acetyl cysteine or a salt thereof.
14. The method of claim 1 , wherein the aqueous dispersion comprises about 0.05 wt.% to about 0.3 wt.% of the N-acetyl cysteine or a salt thereof.
15. The method of claim 1 , wherein the aqueous dispersion comprises about 0.0002 wt.% to about 1 wt.% of the stabilized ascorbate.
16. The method of claim 1 , wherein the aqueous dispersion comprises about 0.03 wt.% to about 0.4 wt.% of the stabilized ascorbate.
17. The method of claim 1 , wherein the aqueous dispersion comprises about 0.05 wt.% to about 0.3 wt.% of the stabilized ascorbate.
18. The method of claim 1 , the method further comprising treating the aqueous dispersion with a cross-linking agent.
19. The method of claim 18 , wherein the cross-linking agent comprises a carbodiimide, epichlorhydrin, hexamethylene diisocyanate, or glutaraldehyde.
20. The method of claim 1 , the method further comprising treating the active layer with a cross-linking agent.