ANTIPERSPIRANT DEVICE AND METHOD

Abstract

A patch and method for capturing perspiration, the patch comprising an absorbent hydrogel layer and a backing sheet adhering to it, the patch preferably comprising a permeable inner membrane and/or a benefit agent embedded in the hydrogel layer.5

Claims

1. A method of capturing perspiration from the human skin, said method comprising the topical application of a patch comprising an absorbent hydrogel layer and a backing sheet adhered to the absorbent hydrogel layer adhering to it, the perspiration being absorbed into the hydrogel layer and thereby trapped.

2. A method according to claim 1, wherein the hydrogel layer comprises a hydrophilic polymer.

3. A method according to claim 2, wherein the hydrophilic polymer is an addition polymer having pendant hydrophilic groups.

4. A method according claim 3, wherein the hydrophilic polymer is poly(2-hydroxyethylmethacrylate) or a metal salt of poly(2-acrylo-2-methyl-1 - propanesulfonic acid).

5. A method according to claim 4, wherein the hydrophilic polymer is a metal salt of poly(2-acrylo-2-methyl-1 -propanesulfonic acid) crosslinked with poly(ethylene glycol) diacrylate.

6. A method according to claim 1 any of preceding claims, wherein the backing sheet comprises a pressure sensitive adhesive.

7. A method according to claim 1 any of prcccding claims, wherein the absorbent hydrogel layer comprises a fragrance and the method also involves the release of said fragrance.

8. A method according to claim 1 any of the prcccding claims, wherein the absorbent hydrogel layer comprises a skin health promoter and the method also involves the release of said skin health promoter.

9. A method according to claim 1, further comprising any of preceding claims which also captures capture of volatile malodourous materials from the human skin.

10. A patch for absorbing perspiration from the human skin comprising an absorbent hydrogel layer, a backing sheet adhered to the absorbent hydrogel layer adhering to it and a permeable inner membrane that is held between the hydrogel layer and the skin when the patch is in use, wherein the hydrogel layer comprises a hydrophilic polymer that is an addition polymer having pendant hydrophilic groups.

11. A patch according to claim 10, wherein the backing sheet comprises a pressure sensitive adhesive.

12. A patch according to claim 10 or 11, wherein the hydrogel layer comprises poly(2- hydroxyethylmethacrylate) or a metal salt of poly(2-acrylo-2-methyl-1 -propanesulfonic acid).

13. A patch according to claim 12, wherein the hydrogel layer comprises a metal salt of poly(2-acrylo-2-methyl-1 -propanesulfonic acid) crosslinked with poly(ethylene glycol) diacrylate.

14. A patch according to claim 10, wherein the patch comprises a tackifier.

15. A patch according to claim 10, wherein all the components of the patch are permeable to air.

Description

EXAMPLES

[0103] The following examples are provided to better illustrate the invention and are not to be considered limiting.

[0104] FIG. 1 shows a cross-section through a patch (1) suitable for use in accordance with the invention.

[0105] FIG. 2 shows how a patch may be located in the underarm region (axilla) and shows a top view of the patch (1).

[0106] FIG. 1 shows that the patch (1) comprises a hydrogel layer (2) sandwiched between a backing layer (3) and a permeable inner membrane (4) that contacts the skin (5). In this embodiment, each of the components is sufficiently flexible to allow the patch (1) as a whole to flex with the movement of the skin of the body to which it is attached.

[0107] FIG. 1 further illustrates the backing layer (3) overlapping the hydrogel layer (2) and making contact with the skin (5) around the periphery of the hydrogel layer (2). The backing layer (3) adheres to the skin (5) in this peripheral region by means of a pressure sensitive adhesive (6) applied on the inner surface of the backing layer (3) around its periphery.

[0108] In FIG. 2, the top view of the patch (1) illustrates a central region (7) and a peripheral region (8) of the patch. In the central region (7), the permeable inner membrane (4), hydrogel layer (2) and backing layer (3) lie one or top of the other. In the peripheral region (8), the backing layer (3) is stuck to the skin (5) by the pressure sensitive adhesive (6).

EXPERIMENTS

[0109] PolyAMPS hydrogel samples were synthesised using the following method. A batch of reaction mixture was prepared from 2-acrylamido-2-methylpropane sulfonic acid sodium salt (NaAMPS, 50% by weight in water, 46.4g in total), poly(ethylene glycol) diacrylate (PEGDA, M.sub.n575 g mol.sup.1, 0.1077 g), water (30.53 g) and the photo-initiator Irgacure 1173 (2-hydroxy-2-methylpropiophenone, 0.1 ml of a 10% aqueous solution). 3 ml samples were transferred to individual moulds and then photo-cured using high intensity UV radiation from a Light Hammer from Fusion UV Systems Corp.

[0110] Sweat patches according to the invention (comprising a polyAMPS hydrogel layer as prepared above) were applied to the underarms of human volunteers. Following vigorous sporting activity, the patches were collected and extracted. Analysis of the extracts was by GC using a Shimadzu GC2014 GC. The retention time of the peaks in the worn sample were identified and compared with known retention times of volatile compounds tested. Linear regression analysis was used to determine the concentration based on pre-prepared calibration curves. GC analysis of the extracts revealed significant levels of acetic acid and propionic acidboth known malodourous components of human perspiration as typically exuded from the underarm regions. This is evidence of the absorption and removal of volatile malodourous materials by the present invention and hence evidence for the deodorancy benefit that it can deliver.