Hydrogel compositions

A translucent hydrogel composition comprising:

• (a) a water-swellable polymer that is insoluble in water at a pH of less than 8.5;
• and
• (b) a blend of a hydrophilic polymer and a complementary oligomer capable of hydrogen bonding to the hydrophilic polymer,
• wherein the relative quantities of the water-swellable polymer, the hydrophilic polymer, and the complementary oligomer are selected so as to render the hydrogel composition translucent.

A translucent hydrogel composition comprising:

• (a) approximately 30 wt. % to approximately 40 wt. % of a cellulose ester composition selected from the group consisting of cellulose acetate butyrate, cellulose acetate propionate, and mixtures thereof;
• (b) approximately 25 wt. % to approximately 30 wt. % of a hydrophilic polymer composed of a poly(N-vinyl lactam);
• and
• (c) approximately 30 wt. % to approximately 35 wt. % of a complementary oligomer capable of hydrogen bonding to the hydrophilic polymer, wherein the complementary oligomer is polyethylene glycol having a molecular weight in the range of 300 to 600.

A wound dressing having a translucent inner region for viewing a covered wound, comprising a substrate having:

• a body facing surface;
• an outwardly facing surface;
• a peripheral skin contact adhesive on the body facing-surface providing means for affixing the wound dressing to a body surface in the region of a wound;
• a translucent inner region;
• and,
• contained within the translucent inner region and on the body-facing surface of the wound dressing, a translucent hydrogel composition for absorbing wound exudate located within a central wound-contacting portion of the wound dressing.

A method of forming a hydrogel film having a discontinuous hydrophobic phase comprising a hydrophobic polymer, a plasticizing elastomer, a tackifying resin, and an optional antioxidant, and a hydrophilic phase that is either discontinuous or continuous, wherein the method comprises:

• melt processing the components of the hydrophobic and hydrophilic phases through an extruder to form an extruded hydrogel composition;
• placing the extruded hydrogel composition on a substrate;
• and
• applying pressure to the hydrogel layer to form a hydrogel film on the substrate.

A method of forming a translucent hydrogel film comprised of a continuous hydrophilic phase, wherein the method comprises:

• melt processing through an extruder a mixture of a cellulose ester composition, a hydrophilic polymer, and a complementary oligomer capable of hydrogen bonding to the hydrophilic polymer, to form an extruded hydrogel composition;
• placing the extruded hydrogel composition on a substrate;
• and
• applying pressure to the hydrogel layer to form a hydrogel film on the substrate,
• wherein the relative quantities of the cellulose ester composition, the hydrophilic polymer, and the complementary oligomer are selected so as to render the hydrogel composition translucent.

A method for preparing a translucent hydrogel film suitable for incorporation into a wound dressing, the method comprising:

• preparing a solution of a cellulose ester composition, a hydrophilic polymer, and a complementary oligomer capable of hydrogen bonding to the hydrophilic polymer, in a solvent;
• depositing a layer of the solution on a substrate to provide a coating thereon;
• and
• heating the coated substrate to a temperature in the range of about 80° C. to about 100° C. for a time period in the range of about 1 to 4 hours, thereby providing a hydrogel film on the substrate,
• wherein the relative quantities of the cellulose ester composition, the hydrophilic polymer, and the complementary oligomer are selected so that the hydrogel film is translucent.