HYDROCOLLOID-BASED WOUND DRESSINGS AND METHODS FOR THE SAME
Hydrocolloid-based wound dressings and backing layers thereof are described. The backing layer may include a carrier film prepared from a carrier film composition. The carrier film composition may include a surface active agent and a combination of first and second aromatic polyester-based thermoplastic polyurethanes. The combination of the first and second aromatic polyester-based thermoplastic polyurethanes may provide a wrinkle-free carrier film under accelerated aging conditions. The hydrocolloid-based wound dressing may include an adhesive layer and the backing layer disposed on the adhesive layer. Methods for preparing the backing layer may include contacting the first aromatic polyester-based thermoplastic polyurethane, the second aromatic polyester-based thermoplastic polyurethane, and the surface active agent with one another to prepare a mixture. The method may also include melting and homogenizing the mixture in an extruder, and extrusion casting the melted mixture on the carrier substrate to prepare the backing layer.
1 . A backing layer for a hydrocolloid-based wound dressing, comprising:
a carrier film, the carrier film comprising a carrier film composition comprising:
a surface active agent; and
a combination of a first aromatic polyester-based thermoplastic polyurethane and a second aromatic polyester-based thermoplastic polyurethane,
wherein the combination of the first aromatic polyester-based thermoplastic polyurethane and the second aromatic polyester-based thermoplastic polyurethane is configured to provide a wrinkle-free carrier film under accelerated aging conditions, and
wherein the surface active agent facilitates the release of the carrier film from a carrier substrate.
2 . The backing layer of claim 1 , wherein the backing layer further comprises a carrier substrate, wherein the carrier film is disposed on the carrier substrate.
3 . The backing layer of claim 1 , wherein the weight ratio of the first aromatic polyester-based thermoplastic polyurethane to the second aromatic polyester-based thermoplastic polyurethane is from about 1.5:1 to about 2.6:1.
4 . The backing layer of claim 1 , wherein the first aromatic polyester-based thermoplastic polyurethane is present in an amount of from about 45 wt % to about 80 wt %, based on the total weight of the carrier film composition.
5 . The backing layer of claim 1 , wherein the second aromatic polyester-based thermoplastic polyurethane is present in an amount of from about 20 wt % to about 40 wt %, based on the total weight of the carrier film composition.
6 . The backing layer of claim 1 , wherein the first aromatic polyester-based thermoplastic polyurethane has a Shore Hardness, as determined according to reference test ASTM D2240, of from about 80 A to about 70 D.
7 . The backing layer of claim 1 , wherein the first aromatic polyester-based thermoplastic polyurethane has a tensile strength, as determined according to reference test ASTM D412/D638, of from about 40 MPa to about 70 MPa.
8 . The backing layer of claim 1 , wherein the first aromatic polyester-based thermoplastic polyurethane has a tensile stress at about 50% elongation, according to reference test ASTM D412/D638, of from about 6 MPa to about 12 MPa.
9 . The backing layer of claim 1 , wherein the first aromatic polyester-based thermoplastic polyurethane has an elongation at break, according to reference test ISO 527-3/5/500 or reference test ASTM D412/D638, of from about 260% to about 320%.
10 . The backing layer of claim 1 , wherein the first aromatic polyester-based thermoplastic polyurethane has a tear strength, according to reference test ISO 34-1B, of from about 65 kN/m to about 85 kN/m.
11 . The backing layer of claim 1 , wherein the first aromatic polyester-based thermoplastic polyurethane has a viscosity at about 23° C. of from about 100 centipoise (cP) to about 200 cP.
12 . The backing layer of claim 1 , wherein the second aromatic polyester-based thermoplastic polyurethane has a Shore Hardness, as determined according to reference test ASTM D2240, of from about 70 A to about 100 A.
13 . The backing layer of claim 1 , wherein the second aromatic polyester-based thermoplastic polyurethane has a tensile strength, as determined according to reference test ASTM D412/D638, of from about 30 MPa to about 70 MPa.
14 . The backing layer of claim 1 , wherein the second aromatic polyester-based thermoplastic polyurethane has an elongation at break, according to reference test ISO 527-3/5/500 or reference test ASTM D412/D638, of from about 350% to about 600%.
15 . The backing layer of claim 1 , wherein the second aromatic polyester-based thermoplastic polyurethane has a melt viscosity at about 204° C., according to reference test ASTM D1084/88, of from about 24,000 cP to about 32,000 cP.
16 . The backing layer of claim 1 , wherein the surface active agent comprises one or more of a silicone, a siloxane, polytetrafluoroethylene (PTFE), an antistatic agent, or a combination thereof.
17 . The backing layer of claim 16 , wherein the surface active agent comprises the siloxane dispersed in an organic resin.
18 . The backing layer of claim 17 , wherein the siloxane comprises a polydimethylsiloxane, and wherein the organic resin comprises a thermoplastic polyurethane resin.
19 . The backing layer of claim 18 , wherein the siloxane is present in an amount of from greater than 0 wt % to about 8 wt %, based on the total weight of the carrier film composition.
20 . The backing layer of claim 1 , wherein the carrier film composition further comprises an additive.
21 . The backing layer of claim 20 , wherein the additive comprises diatomaceous earth.