Topical drug delivery system

• US 5,415,866 A
• Filed: 07/12/1993
• Issued: 05/16/1995
• Est. Priority Date: 07/12/1993
• Status: Expired due to Term

• Current Assignee: Gerald P. Zook
• Original Assignee: Gerald P. Zook
• Inventors: Zook, Gerald P.
• Primary Examiner(s): Page, Thurman K.
• Assistant Examiner(s): Spear, James M.
• Application Number:
  US08/089,192
• Time in Patent Office: 673 Days
• Field of Search: 424/443, 424/447, 424/448, 602/48, 604/303, 604/307, 514/817
• US Class Current: 424/448
• CPC Class Codes: A61K 9/7084 Transdermal patches having a drug layer or reservoir, and one or more separate drug-free skin-adhesive layers, e.g. between drug reservoir and skin, or surrounding the drug reservoir; Liquid-filled reservoir patches

Abstract

A drug delivery system for the topical administration of medication which utilizes a viscoelastic gel pad having a liquid fraction, wherein the medication is incorporated within the liquid fraction, the viscoelastic gel pad being partially encapsulated between two layers of liquid fraction impermeable material which are joined together to form a seal about the periphery of the gel pad so as to control migration of the pad, and the medicating skin contact of the pad is limited to a drug delivery aperture formed in the skin-contacting layer of liquid fraction impermeable material. The aperture-containing layer, which contacts a wearer'"'"'s skin, may be provided with a pressure sensitive adhesive. The invention is exemplified in a topical anesthetic delivery system wherein a viscoelastic gel pad, partially encapsulated by transparent alcohol and water impermeable layers, has an alcohol and water liquid fraction in which is dissolved lidocaine base. The alcohol and liquid fraction of the anesthetic viscoelastic gel pad may be from 20% to 90% alcohol, preferably 70% ethyl alcohol, wherein is dissolved 10% to 40%, by weight, of Lidocaine U.S.P./N.F. Such topical anesthetic drug delivery system can be preliminarily applied with accuracy to a target skin surface by a patient, leaving, upon subsequent removal, a target skin surface anesthetized and ready for immediate dermal surgery or other treatment.

Claims

1. A topical anesthetic delivery system, comprising:

a. a viscoelastic gel pad, having a liquid fraction, a first surface, an opposing second surface and a periphery;

b. said liquid fraction of said viscoelastic gel pad being formed of both alcohol and water, wherein the percentage of said alcohol, by volume, ranges between twenty percent and ninety percent;

said alcohol and water liquid fraction having dissolved therein between ten percent and forty percent, by weight, of lidocaine U.S.P./N.F.;

c. a first layer of alcohol and water impermeable material covering said first surface of said viscoelastic gel pad; and

d. a second layer of alcohol and water impermeable material, having an aperture formed therein of less dimension than said second surface of said viscoelastic gel pad;

said second layer of alcohol and water impermeable material, except for said aperture, covering said second surface of said viscoelastic gel pad;

said aperture being positioned upon said second surface, and within said periphery, of said viscoelastic gel pad;

e. said first and second layers of alcohol and water impermeable material being joined to form a seal about the periphery of said viscoelastic gel pad, so as to encapsulate said viscoelastic gel pad except for said aperture;

f. wherein a portion of said second surface of said viscoelastic gel pad is exposed through said aperture and is held in direct contact with an anesthetic target skin surface when applied to a wearer'"'"'s skin.

2. The topical anesthetic delivery system, as recited in claim 1, wherein said alcohol and water liquid fraction of said viscoelastic gel pad is approximately seventy percent alcohol.

3. The topical anesthetic delivery system, as recited in claim 1, wherein said first and second layers of alcohol and water impermeable material and said viscoelastic gel pad having an alcohol and water liquid fraction are transparent.

4. The topical anesthetic delivery system, as recited in claim 1, wherein, additionally, a means of affixing said second layer of alcohol and water impermeable material to the wearer'"'"'s skin includes pressure sensitive adhesive.

5. A topical anesthetic delivery system, comprising a viscoelastic gel pad, having a liquid fraction, which incorporates an anesthetic in the form of lidocaine U.S.P./N.F. dissolved in an alcohol and water solution, said alcohol and water solution additionally being said liquid fraction of said viscoelastic gel pad;

a. said alcohol and water liquid fraction of said viscoelastic gel pad being approximately seventy percent alcohol; and

b. said alcohol and water liquid fraction of said viscoelastic gel having dissolved therein between ten percent and forty percent, by weight, of lidocaine, U.S.P./N.F.