Crosslinked hydrogel and method for making same

• US 5,120,544 A
• Filed: 06/15/1990
• Issued: 06/09/1992
• Est. Priority Date: 06/19/1989
• Status: Expired due to Term

• Current Assignee: Encore Medical Asset Corporation (Enovis Corp.)
• Original Assignee: Henley International, Inc. (UBS Ag)
• Inventors: Henley, Ernest J.
• Primary Examiner(s): Page, Thurman K.
• Assistant Examiner(s): HORNE, LEON
• Application Number:
  US07/538,778
• Time in Patent Office: 725 Days
• Field of Search: 424/443, 424/445, 424/444, 628/604
• US Class Current: 424/443
• CPC Class Codes: A61F 2013/00919 for physical therapy, e.g. cold or magnetic
• CPC Class Codes: A61F 2013/530481 having superabsorbent materials, i.e. highly absorbent polymer gel materials
• CPC Class Codes: A61F 2013/8479 including electric or magnetic devices
• CPC Class Codes: A61K 47/38 Cellulose; Derivatives thereof
• CPC Class Codes: A61K 9/0009 involving or responsive to electricity, magnetism or acoustic waves; Galenical aspects of sonophoresis, iontophoresis, electroporation or electroosmosis microelectromechanical systems A61K9/0097
• CPC Class Codes: A61K 9/0014 Skin, i.e. galenical aspects of topical compositions non-active ingredients are additionally classified in A61K47/00; A61K9/0009, A61K9/0021, A61K9/7015, A61K9/7023 take precedence; cosmetic preparations A61K8/00, A61Q; preparations for wound dressings or bandages A61L26/00
• CPC Class Codes: A61N 1/0448 Drug reservoir

Abstract

A chemically crosslinked hydrogel includes an active ingredient for transdermal transport selected from the group of lidocainehydrochloride, hydrocortisone, menthol, and methyl salicylate and utilizes as a crosslinking agent an aluminum acetate, which is a polyvalent salt, which renders the resulting hydrogel electrically conductive with a resistance of less than 10,000 ohms per linear centimeter.

Claims

1. A method for providing a crosslinked, conductive hydrogel comprising the steps of:

(a) combining water, carboxymethyl cellulose powder, emulsifies selected from the class of polyethylene glycol, gelatin or lanolin and a biologically active ingredient selected from the class of methol, lidocaine hydrochloride, hydrocortisone or methylsalicylate;

(b) heating the combination to about 160 degrees Fahrenheit for about one hour;

(c) cooling the combination to below 120 degrees Fahrenheit;

(d) adding aluminum acetate to the combination to yield a crosslinked hydrogel;

(e) forming the hydrogel into a desired shape; and

(f) curing the hydrogel.

2. A method as defined in claim 1 wherein the amount of said aluminum acetate added is from about 0.17% to about 0.5% by weight of the combination.

3. A method as defined in claim 1 wherein said forming step comprises spraying said hydrogel onto a conductive carbon or silicon electrode.

4. A method as defined in claim 1 wherein said forming step comprises painting said hydrogel onto a conductive electrode.

5. A method as defined in claim 1 wherein said forming step comprises depositing said hydrogel on a scrim.

6. A method as defined in claim 1 further comprising encasing said hydrogel and scrim between layers of release paper.

7. A method as defined in claim 1 wherein said forming step comprises depositing said hydrogel on a cellulose scrim.

8. A method as defined in claim 1 wherein said forming step comprises feeding the release paper, scrim, and uncured gel through rollers.