GB2448855A

GB2448855A - Pressure activated transdermal medicament delivery system

Info

Publication number: GB2448855A
Application number: GB0708647A
Authority: GB
Inventors: Mark Stephen Couchman
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-05-04
Filing date: 2007-05-04
Publication date: 2008-11-05
Anticipated expiration: 2027-05-04
Also published as: GB2448855B; GB0708647D0

Abstract

A skin dressing pouch for controlled release of a substance which comprises a continuous transparent flexible semi-permeable polymer membrane 1 having an adhesive skin-contacting surface 5 surrounding an aperture 3. Enclosed within the cavity 2 of the pouch is an impermeable polymer compartment 4 containing an active agent, medicament or solution 7. Applying finger pressure to the pouch ruptures the compartment 4 and releases the agent 7 through the aperture 3 for localised containment and retention of the substance on the skin to promote healing. The dressing forms a hermetic seal around the aperture 3 and is watertight. The dressing includes a detachable protective covering 6. Preferably the compartment 4 is visibly demarked to identify its location within the cavity 2. The pouch and/or the active ingredients 7 may be sterilized by gamma radiation.

Description

PRESSURE ACTIVATED TRANSDERMAL MEDICAMENT DEL IVERY

SYSTEM

Human skin is normally a flexible impermeable two way barrier, protected and kept supple by its secretion of natural oils. These oils help to lubricate the skin and when mixed with water form a hydrolipid film that prevents water loss through evaporation. Normal skin is 10-20 per cent water by weight. This level of hydration is largely dependant on water being transferred by osmosis from the lower dermal layer to the upper epidermal layer. If the water content of the skin should fall below 10 per cent, the cellular structure of the uppermost layer the stratum comeum becomes dehydrated resulting in dryness, loss of elasticity and fissuring, which can expose the deeper layers to physical or chemical trauma.

The treatment of clinically dry skin often involves the use of hydrative emollients, which work by providing an oily film over the skin's surface to assist the natural water retaining barrier and improve cellular hydration.

The application of an emollient however can be compromised by normal everyday activity whereby it can be inadvertently removed by regular bathing, frictional or absorbent clothing. Simple routines during bathing for example, such as the use of hot water, towel drying, harsh soaps, can all remove surface barriers and moisture from the skin. Emollients used therefore in the treatment of clinically dry skin would be used to better effect if such applications could be retained in contact with the skin for a longer duration.

The present invention relates to a self adhesive confonnable semi-permeable, apertured, skin dressing pouch, containing within its cavity an impermeable bubble-like compartment accommodating a therapeutic agent. On adhesion of the pouch to the surface of the skin by means of a pressure sensitive skin contacting adhesive, direct or indirect pressure applied to the bubble-like compartment through the upper membrane of the pouch facilitates its rupture dispersing the contained therapeutic agent into the pouch cavity and in contact with a localized dermal area defined by an aperture hermetically sealed at its perimeter upon adhesion to the surface of the skin.

The skin dressing pouch enables a therapeutic agent, medicament or solution to be applied aseptically to a localized dermal area for the purpose of promoting and healing skin lesions through containment and retention thereof and prevents inadvertent removal during normal everyday activity.

References: Dr Jay Herbert 1998. A Guide to dry skin problems. JCN Journal.

Volume 12: Issue 11.

Claims

Claims What is claimed is: I. A skin dressing pouch for finger pressure controlled release of an active agent, medicament, or solution from an impermeable polymer compartment within a skin dressing pouch to an aperture sealed at its perimeter upon adhesion to the surface of the skin, for promoting and healing of lesions by localized containment and retention thereof, comprising, a flexible, conformable, transparent semi-permeable polymer skin dressing pouch, having upper and lower walls which are continuous, the skin facing said lower wall of the skin dressing pouch contains an aperture of variable size or shape visibly demarked at its border enabling the said aperture in the said skin dressing pouch to be identified through the said upper wall of the said skin dressing pouch prior to its adhesion to the skin, the skin facing side of the said lower wall of the said skin dressing pouch has across its entire surface a breathable, pressure sensitive, skin contacting adhesive, shielded before use by a removable covering which is detachably affixed to the said skin contacting adhesive over its entire surface inclusive of the said aperture to prevent contamination of the cavity area within the said skin dressing pouch during storage, the said pressure sensitive skin contacting adhesive on the said skin facing side of the said lower wall of the said skin dressing pouch forms a hermetic seal around the said aperture on gentle pressure applied through the said upper wall of the said skin dressing pouch thus effecting a watertight seal around the said aperture defining the skin treatment area, within the said cavity of the said skin dressing pouch, affixed to the inner surface of the said semi-permeable continuous polymer wall is located an impermeable polymer compartment of variable shape or size for the sealed containment and subsequent finger-pressure release of a chosen medicament, active agent, substance, or solution when direct or indirect said finger pressure is applied to said impermeable polymer compartment through the said upper semi-permeable wall of the skin dressing pouch, whereupon the resultant increase in hydrostatic pressure within the said impermeable polymer compartment is sufficient to rupture the membrane of the said impermeable polymer compartment thus releasing the said medicament, active agent, or solution into the sealed said cavity of the said skin dressing pouch and in contact with a localized area of skin defined by the said aperture.

1. The skin dressing pouch of claim 1, wherein said semi permeable skin dressing pouch comprises of a microporous polymer film, such as those constructed from stretched polytet-rafluoroethylene (PTFE), diverse polyolefins, or precipitation-cast polyurethane, impermeable to fluids and bacteria but permeable to air and water vapour.

2. The skin dressing pouch of claim 1, wherein said pressure sensitive adhesive comprises of an acrylic ester co-polymer containing hydrophilic groups enabling permeability to oxygen and moisture vapour but is unaffected by and impervious to water.

3. The skin dressing pouch of claim 1, wherein said semi permeable skin dressing pouch is transparent or translucent.

4. The skin dressing pouch of claim 1, wherein said impermeable polymer compartment within the said skin dressing pouch is visibly demarked so as to identify its location within the said cavity.

5. The skin dressing pouch of claim 1, wherein said removable covering comprises of siliconized paper.

6. The skin dressing pouch of claim 1, wherein said removable covering which is detachably affixed has an easy peel tab on its outer edge for ease of removal.

7. The skin dressing pouch of claim 1, wherein said skin dressing pouch is variable in size, shape or conformity consistent with the skin area or lesion to be treated.

8. The skin dressing pouch of claim 1, wherein said skin refers to mammalian skin.

9. The skin dressing pouch of claim 1, wherein said skin dressing pouch is packaged in a protective bacteria proof packet.

10. The skin dressing pouch of claim I, wherein said skin dressing pouch is sterilized by gamma radiation.

11. The skin dressing pouch of claim 1, wherein said active agents, rncdicaments, or solutions where appropriate are sterilized by gamma radiation.

Drawing: A specific embodiment of the aforementioned invention will be described by means of example with references to the drawings contained herein in which:-Figure 1 shows a cross section of the skin dressing pouch: Figure 2 shows a cross section of the skin dressing pouch in relation to the surface of the skin with the detachable adhesive backing removed from the skin dressing pouch; and Figure 3 shows an aerial view of the skin dressing pouch.

Referring to the drawing of Figi which shows the skin dressing pouch comprising of a continuous semi-permeable polymer membrane I which has on its skin facing lower wall 1 an aperture 3 of variable size or shape, which determines the skin surface area to be exposed to the medicament, active agent, or solution 7 contained within a non permeable polymer compartment 4.

The skin facing side of the continuous semi-permeable polymer membrane 1 has attached to its entire surface a skin contacting pressure sensitive adhesive 5 which with gentle pressure forms a hermetic seal with the skin 8 around the aperture 3.

The pressure sensitive skin contacting adhesive 5 has a detachable protective covering 6 which remains in contact with the pressure sensitive skin adhesive 5 across its entire surface inclusive of the aperture 3 to protect the inner cavity 2 of the skin dressing pouch from external contamination. The drawing of Fig 2 shows the detachable protective covering 6 removed prior to the pouch being applied to the skin's surface 8. Within the cavity 2 of the skin dressing pouch affixed to the internal surface of the semi-permeable membrane I is affixed an impermeable polymer compartment 4 of variable size or shape. Finger pressure 10 applied directly or indirectly through the upper surface of the continuous semi permeable polymer membrane 1 upon the impermeable polymer compartment 4 increases the hydrostatic pressure sufficiently to rupture the impermeable membrane 4 thus releasing the medicament, active agent, or solution 7 within the cavity 2 of the skin dressing pouch 1. The medicament, active agent, or solution 7 is dispersed within the sealed cavity 2 of the pouch and subsequently brought into contact with the exposed area of skin determined by the aperture 3 in the skin dressing pouch.