CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. provisional patent application serial number 61/089,365 filed on 08/15/2008, entitled "Multiple Cell Diffusion Dressing", which is included herein at least by reference.

BACKGROUND OF THE INVENTION

1. Field of the invention:

This invention is in the field of medical technology, and pertains in particular to delivery of oxygen and/or other gasses or compounds to tissue wounds by diffusion.

2. Discussion of the state of the art:

It is by the time of the present application well-known in the art that therapeutic agents may be delivered as gaseous matter to the site of a tissue wound to aid in certain aspects of recovery. Such agents may include for example, antibiotic agents to avoid infection, and delivery of oxygen to speed the healing process. A number of patents have been issued to various inventors that collectively teach local generation of oxygen, for example, at a wound site through bandage systems using chemical reactions, oxygen saturated solutions, or electrochemical generators. Several such patents are listed in an Information Disclosure Statement filed with this patent application.

Supplying Oxygen and other therapeutic agents to a wound site on a continuous and ambulatory basis is therefore known to be of benefit to speed healing and reduce infection. There are still unmet needs in such systems, such as even area distribution of the therapeutic agents to the affected tissue. Thus, more efficient and easier-to-use systems are desirable. SUMMARY OF THE INVENTION

The problem stated above is that it is desirable for tissue treatment that a dressing is provided with diffusive properties for extended and uninterrupted treatment by one or more therapeutic agents, but current diffusion dressings are unable to provide an evenly distributed therapeutic regimen that is efficiently activated and simple to initiate.

The inventors therefore considered functional elements of therapeutic tissue dressings looking for elements that exhibit specific material properties could potentially be harnessed to provide a diffusion dressing but in a manner that would not create complex or present problems with uneven distribution of therapeutic agent.

The present inventor realized in an inventive moment that if, at the point of application, therapeutic agents could be caused to diffuse more equally and at a better regulated rate, significant improvement in tissue recovery might result. The inventor therefore constructed a unique diffusion dressing for treating tissue that allowed gases to diffuse equally relative to targeted tissue area and at a controlled and uniform rate across the footprint of diffusion, but constrained therapeutic agents save some desired vapor emissions from escaping the dressing in any direction other than into the tissue being treated. A significant therapeutic recovery rate results with no added risk of infection, maceration, dryness, or other tissue healing problems created or elevated.

Accordingly, in one embodiment of the invention a diffusing device for treating tissue is provided comprising multiple cells arranged in a cell layer, the cells filled with or charged with a therapeutic agent, an occlusive layer in direct communication with the cell layer, and a diffusion layer in direct communication with the cell layer. The diffusing device is sealed peripherally about an area of tissue to be treated and wherein the therapeutic agent is released from the cells through the diffusion layer based on the diffusion properties of the diffusion layer.

In one embodiment the therapeutic agent is one of a gas, a gel, or an emulsion containing a gas. In variations of this embodiment the therapeutic agent is one of oxygen, nitric oxide, or carbon monoxide. In one aspect of this embodiment the therapeutic agent includes one or more synthetic drugs.

In a one embodiment the multiple cells are juxtaposed in the cell layer and separated by cell walls. Alternatively, the multiple cells are juxtaposed in the cell layer and separated by cell walls and hollow spaces. In a variation to this embodiment the hollow spaces may be cells filled with an absorbent material.

In one embodiment the diffusion device further has an adhesive perimeter for sealing the device over a targeted tissue area. In one embodiment the diffusing device has a shape with a predicable finite length and a predictable finite width dimension. Alternatively, the device has an indeterminate shape with at least one dimension being variable depending on cut length.

In one embodiment the diffusing device further has an absorbent layer disposed immediately adjacent to and in front of the diffusion layer, the absorbent layer making intimate contact with the targeted tissue area. In another embodiment the diffusing device including the absorbent layer further includes a backup absorbent layer disposed immediately adjacent to and behind the diffusion layer.

In one embodiment the diffusing device further has multiple perforations strategically located through vertical cell walls of the cells in the cell layer. In a variation of this embodiment the perorations are micro-perforations. In one embodiment the diffusion layer is one of an organic material or a compound containing organic and synthetic materials. In one embodiment cell layer is one of an organic material treated for impermeability to a therapeutic agent. In one embodiment including an adhesive perimeter, the seal formed by the perimeter is a hermetic seal. In one embodiment the defusing device further has an additional occlusive layer disposed immediately adjacent to and behind the layer attached over the cell layer wherein the additional layer is manually removable.

According to another aspect of the invention a method is provided for treating an area of tissue using a diffusion device having multiple cells arranged in a cell layer, the cells filled with or charged with a therapeutic agent comprising the steps (a) pre- filling, pre-charging, or preloading, the cell layer of the device with a therapeutic agent, (b) positioning the device over the tissue area to be treated and sizing the device if necessary, and (c) sealing the device to the tissue around a perimeter of the diffusing area of the device.

In one aspect of the method in (a), the therapeutic agent is one of a gas, a gel, or an emulsion containing a gas. In another aspect the therapeutic agent is one of oxygen, nitric oxide, or carbon monoxide. In one aspect the therapeutic agent contains one or more synthetic drugs. In one aspect of the method in (b) the device is sized by cutting a length of the device from a roll of undetermined length.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

Fig. 1 is a cross-sectional view of a multi-celled diffusion dressing in an embodiment of the present invention. Fig. 2a is a plan view of a dressing according to an embodiment of the present invention, the dressing having a finite shape.

Fig. 2b is a plan view of a dressing according to an embodiment of the present invention, the dressing having a finite shape in one direction, and an undetermined shape in a second direction in the same dimension. Fig. 3 is a cross-sectional view of a dressing according to an alternative embodiment of the present invention.

Fig. 4 is a cross-sectional view of a dressing according to another alternative embodiment of the present invention.

DETAILED DESCRIPTION

The inventor provides a device that may be used in an ambulatory fashion to deliver a therapeutic agent, for instance a gas, to a tissue to be treated through a diffusion process. The device enables the targeted tissue to be exposed to the therapeutic agent for a period of time, typically days. The device includes multiple separate cells or reservoirs as opposed to a single cell or reservoir. The present invention is described in enabling detail in the following embodiments.

Fig. 1 is a cross-sectional view of a multi-cell diffusion dressing 100 in an embodiment of the present invention. Diffusion dressing 100 is also termed a diffusion device and may be referred to herein as a device or dressing in its various forms. Device 100 is adapted to deliver a therapeutic agent by diffusing the agent through a specific device diffusion layer 104 that covers the bottom open area of a plurality of cells 101. Cells 101 arranged in a layer may each separately define a volume and may be arranged in a juxtaposed or side-by-side fashion within the layer. Such an array of multiple cells 101 may be ordered in even rows of cells the rows placed side-by-side. The array of cells may also be random or honeycombed. It is not required that all of the cells be exactly the same size with respect to volume definition, wall thickness, shape, or height dimension.

Cells 101 may be manufactured of a polymer-based medical grade material such as polyurethane. Other synthetic materials such as Ethylene-Vinyl Acetate may be used to form the cells. It is preferred that the cells are impermeable to the therapeutic agent stored within each cell volume. In one embodiment an organic cellulose material may be used provided that it is treated for impermeability with respect to leakage of therapeutic agents through the cell walls or cell tops. Diffusion layer 104 may be manufactured of a permeable material that may be compatible to attachment methods for attaching the diffusion layer directly over the cell openings to enable therapeutic agent 2 to defuse from the reservoirs to the treated tissue over a period of time. In one embodiment, the material is a thin sheet of polyurethane that is made permeable through application of a specific diffusion pattern of micro perforations or openings (not illustrated). Differing patterns, sizes and shapes of perforations may be provided in diffusion layer 104 to regulate the amount of therapeutic agent that reaches the tissue over time. In one embodiment diffusion layer 104 is an organic coating that is porous when set and exhibits the desired diffusion properties. In another embodiment, diffusion layer 104 is a viscous compound of organic and synthetic substances that when mixed and applied as a coating, exhibit the desired diffusive characteristics. Diffusion layer 104 is preferably permeable as described above and allows therapeutic agent 102 to diffuse over periods ranging from minutes to several days, weeks, or longer.

Device 100 may be charged with a therapeutic agent 102 or may be a vehicle through a therapeutic agent is delivered upon subsequent charges. Therapeutic agent 102 may be a gas, such as oxygen, nitric oxide, carbon monoxide, a gel, or an emulsion containing a gas. The therapeutic agent may or may not contain drugs such as antibiotics or other therapeutic drugs used in treatment of tissue wounds. The exact agent and any mediums or additional drug compounds or cocktails used with device 100 may vary as there are many different types of tissue wounds requiring different types of treatments. For example, burns, skin grafts, and infections all remarkably different types of wounds requiring very different treatments.

Device 100 may include an optional occlusive layer 103 that covers the top of the juxtaposed cell layer (101). Layer 103 may be provided to prevent any therapeutic agent from escaping the dressing through the top of the cellular structure if the structure fails to form a tight seal. Layer 103 is made of a material impermeable to the therapeutic agent stored into cells 101. In a preferred embodiment occlusive layer 103 is impermeable to the therapeutic agent, but allows vapor transfer to the outside of the device. Such material can be polyurethane, Ethylene- Vinyl Acetate, or others.

In one embodiment an optional layer 105 may be provided to dressing 100 beneath the diffusion layer 104. Layer 105 is absorbent in a preferred embodiment, but does not change volume when absorption of moisture or other exudates occurs. Layer 105 may contact the skin directly and is porous enough as to not interfere with the diffusive properties of layer 104. Layer 105 may be provided using any synthetic or organic/synthetic material that absorbs liquids but does not significantly change thickness due to absorption. Layer 105 may be impermeable or may have a low permeability to the therapeutic agent. At the same time layer 105 allows vapor transfer from the skin or other tissue to diffuse back through the device. These properties can be realized using a single layer exhibiting all of the properties or a combination of individual layers, each having one of the properties described above. Device 100 may be applied to a tissue area using an adhesive peripheral layer

106. Layer 106 as an adhesive to hold device 100 in place, is applied to healthy tissue around the tissue targeted for treatment. Standard medical adhesive tape may be used to form this layer around the dressing. The seal prevents any therapeutic agent from escaping to the outside of the dressing.

Fig. 2A is a plan view of dressing 200 according to an embodiment of the present invention, the dressing having a dimensionally finite shape. Fig. 2B is a plan view of a dressing 203 according to an alternate embodiment of the present invention, the dressing having an undetermined shape where one dimension is variable.

Referring now to Fig. 2A, dressing 200 is prefabricated in the form of a finite shape like a rounded rectangle or square. Other geometric shapes may be observed as well without departing from the spirit and scope of the invention. In this example, device 200 is a rounded rectangle in geometric footprint. Device 200 includes a footprint 201 where diffusion takes place. Footprint 201 defines the area of the juxtaposed cells described further above. Device 200 has a perimeter footprint 202 where a seal is formed between the device and healthy tissue surrounding the target tissue to be treated. Footprint 202 defines an area of adhesive in the form of tape or treated surface.

Device 200 has a length dimension A and a width dimension B that are both predictable such that the device may be acquired in the desired finite shape having the predictable dimensions. There may be a variety of finite shapes and sizes available in standalone packaging or in assorted collections including devices of varying shapes and sizes.

Referring now to Fig. 2B, device 203 is illustrated having a same width dimension B as the device of Fig. 2A but having a variable length dimension X that is determined by the user. In this case device or dressing 203 may be cut to a determined length X from a roll of material of undetermined length. In this example, a footprint 204 on opposite sides of the device relative to the predictable width B represents the adhesive sealing surface for sealing the device to tissue along those edges. The fact that the device was cut from a roll of material causes a lack of sealing area for the ends of the device assuming two cut lines. Therefore, a user may have to add some adhesive tape to the ends of device 203 for seal purposes. In one embodiment the device may be shaped to size by trimming or cutting and then sealed to an area using sealing adhesive tape adapted for the purpose. In another embodiment to device may be held in place by a wraparound dressing such as gauze, cheesecloth, or a sports wrapping like a soft brace material.

Fig. 3 is a cross-sectional view of a dressing 300 according to an alternative embodiment of the present invention. Defusing device 300 includes a layer of cells

301 filled with a therapeutic agent 302 as described further above with reference to Fig. 1 (cells 101, therapeutic agent 102). However, in this case the openings of cells 301 facing a diffusion layer 305 are covered with an absorbent layer 304.

Absorbent layer 304 may be a fast absorbing synthetic or polymer-based material that absorbs moisture including exudates from the targeted tissue area being treated. In this example, diffusion layer 305 is permeable to moisture and exudates from the damaged tissue or wound and allows the absorbent materials to accept the moisture, etc. through the layer. In an optional variation to this embodiment a second absorbent layer 307 may be provided ahead of diffusion layer 305 to make direct contact with the tissue. Absorbent layer 304 may be rated for super absorption in order to provide adequate divertive absorption keeping absorbent layer 307 dry and viable for an extended period. An adhesive layer or sealing layer 3006 is provided around the perimeter of device 300 for sealing the device to preferably healthy tissue. Fig. 4 is a cross-sectional view of a dressing 400 according to another alternative embodiment of the present invention. Diffusing device 400 includes a cell layer wherein the individual cells 401 are arrayed in a layer and wherein the cells 401 are filled with a therapeutic agent 402. However, in this embodiment, there is space in-between and surrounding each cell 401 that is filled with an absorbent material 403. The space may be an adjacent cell filled with absorbent material instead of therapeutic agent such that a portion of the cells diffuse therapeutic agent into the targeted tissue while a portion of the cells are engaged in absorbing moisture and exudates from the tissue.

In a variation to the embodiment described above, individual vertical cell walls forming cells 401 may have micro-perforations or larger perforations strategically placed therethrough to increase the transferability of moisture over the footprint of the diffusing area of the device relative to the absorption cells filled with absorbent material 403. Absorption cells may be symmetrically located throughout the footprint to insure significantly constant absorbent capabilities across the footprint. The perforations may also be present in an embodiment where the cells are all filled with therapeutic agent and only the cell walls separate one cell from another in the cell layer. In this case diffusion properties may be enhanced by restricting but not eliminating altogether cross-migration of therapeutic agents across a diffusion area. Such a diffusion perforation pattern described above may help to equalize gaseous pressure across the device be allowing adjacent cells to communicate with one another in a controlled manner. Device 400 may be covered on top with a permeation layer 404, which is adapted as a permeation layer for vapor transfer and to prevent bacterial contamination. Device 400 also includes a diffusion layer 405 analogous to those described above. In this example as in other embodiment already described, an optional absorbent layer 407 can be added beneath the diffusion layer for directly contacting the affected tissue. An adhesive layer 406 is analogous to adhesive layers previously described above.

In all embodiments the cell layer material should be impermeable to the therapeutic agent stored therein. The material should however allow transfer of vapors to the outside. A suitable material could be polyurethane, ethylene-vinyl acetate, or other materials. Absorbent materials may be those that absorb moisture and/or exudates from the tissue being treated without changing in volume any significant amount. Top layers such as layer 404 in this example are vapor transfer barriers allowing tissue to dry and preventing maceration. These layers are preferably impermeable to the therapeutic agents. One with skill in the art of diffusing dressing construction and use will appreciate that there are a variety of ways to layer elements to provide function without departing from the spirit and scope of the present invention. For example, in one embodiment, an occlusive layer (not illustrated) may be provided to cover the top vapor transfer layer and which may be peeled off by a user to activate vapor transfer properties when the device is in use. Also in a preferred embodiment the layer around the edges of the device connecting the top layer to the adhesive layer is occlusive to prevent escape of therapeutic agents.

In another embodiment absorbent layers 105 (Fig. 1), 304 and 307 (Fig. 2), and 403 and 407 (Fig. 4) can be infused or impregnated with a substance such as a biocide, a drug, an antimicrobial agent, an anti inflammatory agent, an analgesic anesthetic or some other pharmaceutical. Such infused chemical agents may be carried along with the diffusion of the therapeutic agent or they may be dissolved (depending on the agent type) in presence of moisture from the tissue. An example of such a process would be the release of chloride dioxide impregnated into any of the above-described absorbent layers to provide antimicrobial properties to the device.

It will be apparent to one with skill in the art that the diffusing device dressing of the invention may be provided using some or all of the mentioned features and components without departing from the spirit and scope of the present invention. It will also be apparent to the skilled artisan that the embodiments described above are exemplary of inventions that may have far greater scope than any of the singular descriptions. There may be many alterations made in the descriptions without departing from the spirit and scope of the present invention.

HERMETICALLY SEALED PACKAGE FOR A THERAPEUTIC DIFFUSION

DEVICE

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. provisional patent application serial number 61/089,374 filed on 08/15/2008, entitled "Method and Apparatus for Packaging a Diffusion Device," which is included herein at least by reference.

BACKGROUND OF THE INVENTION

1. Field of the invention: The present invention is in the field medical technologies and more particularly the treatment of tissue via a diffusion type device, the invention pertaining to packaging of such devices for transport and storage before use.

2. Discussion of the state of the art: In the medical field it is often required to treat tissue of patients in a manner which requires an extended period of bandaging or covering with medication diffusing patches or like devices that work to keep tissue moist, promote healing, to prevent maceration, possible infection, or to prevent any jolting or other physical disruption of a particular tissue area. One example of such a therapeutic device is a multilayered diffusion dressing or device typically applied over a wound or graft to promote new skin growth in an area where the original skin was lost or removed by surgery. Such devices have different names in the art but may be technically referred to as therapeutic diffusion devices because of an active delivery (diffusion) of some therapeutic agent, often delivered in the form of a gas through an interfacing diffusion layer of the dressing or device to the affected tissue over time. Such devices may vary architecturally according to therapeutic need. For example the therapeutic agent may be a gas, a salve, an antibiotic, a growth hormone, or a mixture of agents. In many cases a medium is also present in the device to help contain and deliver the agent. One problem with such diffusion devices is that, unless contained, they have no shelf life once created from the materials and therapeutic substances required to promote recovery in particular tissue conditions. The products are often built for the purpose at the time they are needed. Currently tissue-targeted therapeutic diffusion devices are available off-the-shelf that can be safely stored until such time that the device may be required for use on a patient. However, one limitation of these devices known to the inventor is that they must be kept in a pouch or similar container and removed from the pouch before use.

Therefore, what is clearly needed is a hermetically sealed package for diffusion devices and methods of fabrication thereof to preserve the integrity of the therapeutic agents and mediums within the device for storage and transport before needed in the field.

SUMMARY OF THE INVENTION

The problem stated above is that for a diffusion dressing, there are no reliable means for preserving therapeutic agents from the time of manufacture to the time of use of the products to treat tissue aside from containment of the dressing in a pouch or similar container. Many patients have diffusion bandages that wear out, become unsealed, and are not reliably refillable with new agent during a course of treatment. The inventors therefore considered functional elements of a diffusion dressing, looking for elements that exhibit impermeable and permeable properties that could potentially be harnessed to provide shelf life for stored therapeutic agents and breathability in some cases for tissue dressings but in a manner that would not present problems or hardships for users. Every diffusion dressing is charged with some therapeutic agent that is expelled from the device through a diffusion process one effect there being that the dressing eventually becomes depleted of agent and is no longer effective. Most such diffusion devices employ gasses infused into a reservoir in the device, the gases being diffused into a tissue area through a special diffusion layer of the device. Diffusion layers and adhesive layers for application of the dressing over a wound are typically a part of such apparatus.

The present inventors realized in inventive contemplation that if, at the point of manufacture, therapeutic gasses could be preserved within a diffusion dressing for an extended period of time, significant convenience might result for practitioners and patients. The inventor therefore constructed a unique packaging arrangement for diffusion devices that allowed gases to be stored within such devices for an indeterminate period and that allowed the packaged devices to be activated to diffuse the gasses at the appropriate time when sealing the device over the tissue to be treated. A significant improvement in therapeutic benefit resulted with no impediment to practitioners or patients use of such diffusing devices created.

Accordingly, in an embodiment of the present invention, a method is provided for packaging a diffusion device for treating tissue, the device including more than one device layer and at least one reservoir containing a therapeutic agent comprising the steps (a) positioning the diffusion device over top of a first packaging layer; (b) positioning a second packaging layer over top of the diffusion device and the first packaging layer; and (c) forging a seal, the seal incorporating at least the first packaging layer and the second packaging layer.

In one aspect of the method the first and second packaging layers are one of Polyvinylidene Chloride or Polyurethane. In one aspect in step (a) the first packaging layer has a peripherally disposed sealing surface and in step (b) the second packaging layer has a peripherally disposed sealing surface. In one aspect in step (c) the seal is forged using heat and pressing the layers together. In one aspect variation in step (c) the seal includes a device layer and the device layer is an adhesive layer. In another aspect variation, in step (c) the seal is an adhesive bead applied to the peripheral edges of the first and second packaging layers. In a preferred aspect the seal is a hermetic seal.

According to another aspect of the present invention, a method is provided for packaging a diffusion device for treating tissue, the device including more than one device layer and at least one reservoir containing a therapeutic agent comprising the steps (a) positioning the diffusion device over top of a packaging layer, and (b) forging a seal between the packaging layer and a device layer. In one aspect of this method, the device layer is an adhesive layer. In one aspect in step (b) the seal is forged using heat and pressing the layers together. In one aspect of the method, the packaging layer is one of Polyvinylidene Chloride or Polyurethane. In one aspect in step (b) the seal is an adhesive bead running peripherally about the device.

According to another aspect of the invention, a method is provided for packaging a diffusion device for treating tissue, the device including more than one device layer and at least one reservoir containing a therapeutic agent comprising the steps (a) positioning the diffusion device over top of a first packaging layer, (b) placing a second packaging layer over the uppermost device layer of the device, (c) forging a seal between the second packaging layer and the uppermost device layer, and (d) forging a seal between the first packaging layer and an intermediate device layer. In one aspect of this method, in step (c) the second packaging layer is not peeled off until sometime after applying the device to an area of tissue to allow the device to breathe. In one aspect of the method in step (d) the intermediate device layer is an adhesive layer. Also in one aspect the first and second packaging layers are Polyvinylidene Chloride or Polyurethane. In another aspect of the invention, a package is provided for a diffusion device, the device including more than one device layer and at least one reservoir containing a therapeutic agent. The package includes at least one packaging layer, and at least one sealing surface disposed along one or more edges of the packaging layer. The packaged is characterized in that the sealing surface engages one of a device layer or another packaging layer to form the package. In one embodiment the at least one packaging layer is a Polyvinylidene Chloride or a Polyurethane and the sealing surface is activated by heat treatment. In one embodiment the package includes two packaging layers incorporated independently of one another while enclosing a diffusion device. In one embodiment a packaging layer includes one or more sub-layers that are removable.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

Fig. 1 is an elevation view of a packaged diffusion device according to an embodiment of the present invention.

Fig. 2A is a partial view of a packaged diffusion device with a peripheral multi-layered seal.

Fig. 2B is a partial view of a packaged diffusion device with a peripheral bead seal.

Fig. 3 is an elevation view of a diffusion device packaged according to an alternate embodiment.

Fig. 4A is a partial view of a packaged diffusion device with a multi-layered seal. Fig. 4B is a partial view of a packaged diffusion device with a peripheral bead seal.

Fig. 4C is a partial view of a packaged diffusion device with the seal located more inward and away from the peripheral edge if the device.

Fig. 5 is an elevation view of a package diffusion device according to a further embodiment of the invention.

DETAILED DESCRIPTION

The inventors provide a method for containing a therapeutic agent, for example a gas, in a diffusion device. The method enabled by apparatus also protects such devices from leaking therapeutic agents or mediums and prevents specific outside elements from entering the volume or volumes of such devices and diluting or corrupting therapeutic agents.

Fig. 1 is an elevation view of a packaged diffusion device 100 according to an embodiment of the present invention, diffusion device 100 is typical of a diffusion dressing known to the inventor and includes a diffusion layer 103 through which a therapeutic agent stored in volume 102, for example, diffuses into a tissue wound or other targeted tissue. Device 100 includes an occlusive layer 101 that is impermeable to the therapeutic agent in a preferred embodiment. An adhesive layer 104 may be provided peripherally around the diffusion device for enabling device adhesion to tissue to be treated. In a preferred embodiment, the seal is hermetically applied.

In this example device 100 has a finite shape with predictable dimensions. In one embodiment however, device 100 may be cut from a roll leaving the longitudinal dimension variable. Occlusive layer 101 may, in one embodiment, be somewhat permeable to the therapeutic agent stored in volume 102 without departing from the spirit or scope of the present invention.

The inventor provides packaging to device 100. Without packaging device 100 may typically be filled with gel, emulsion, gas or any other medium containing therapeutic agent, or ambient air at the time of need of the agent. Diffusion layer 103 begins diffusing therapeutic agent immediately after charging the device.

Diffusion device 100 is packaged in this embodiment by placing the device between two separate packaging layers. A top packing layer 105 is provided to cover the top area of diffusion device 100. A bottom packing layer 106 is provided to cover the bottom area of device 100. Layers 105 and 106 may be manufactured of the same material, preferably impermeable to therapeutic agents and delivery mediums, as well as the outside air.

Layers 105 and 106 may be oriented such that they are symmetrically opposed during packaging with the diffusion device positioned there between. Layers 105 and 106 may be manufactured of Polyvinylidene chloride or other poly-based materials. Other materials that are impermeable to therapeutic agents and mediums used in the diffusion device may include certain metallic based materials, other inorganic materials or a combination of these. It is desired that the material be flexible and seal able to other typical device layers.

In this example a hermetic seal 108 is applied about the periphery of package

100 and involves top packing layer 105, adhesive layer 104, and lower packing layer 106. Adhesive layer 104 may incorporate layers 101 and 103 without packaging. Seal

108 prevents escape of any therapeutic agent or medium from anywhere within the package. Volume 102 may be filled or charged with therapeutic agent at the time of packaging, preferably after a seal 108 is substantially complete. This is because gas will immediately diffuse through diffusion layer 103 when the device is charged. In one embodiment a one-way valve stem (not illustrated) is provided and adapted to accept compressed agents into one or more reservoirs of the diffusion device. In that case the packaging incorporates the valve stem in its design.

A packaging volume 107 is created by virtue of the sealing of layers 105 and

106 about the diffusion device. Volume 107 may be filled with the same therapeutic agent that the diffusion device is filled with and at a specific pressure to equalize the pressure within the device and the package effective preventing diffusion of the internal therapeutic agent from within the device into the packaging. In this way, device 100 may be stored in a charged state and used at a time when it is needed.

Packaging layer 106 may be removed just before device application to tissue thereby activating the diffusion of the device. In another embodiment, the device may be charged and recharged with therapeutic agent as needed while being stored or while in use treating tissue.

Fig. 2A is a partial view of a packaged diffusion device 200 with a peripheral multi-layered seal. Fig. 2B is a partial view of a packaged diffusion device 202 with a peripheral bead seal. Referring now to Fig. 2A, device 200 is analogous to device 100 described above with respect to Fig. 1. Diffusion layer 103 and occlusive layer 101 define the diffusion device. Adhesive layer 104 is also apparent on device 200.

Device 200 may be sealed to packaging layers 105 and 106 by a hermetic seal

201 that incorporates the multiple layers into the seal. Application of adhesive to all of the layer surfaces may be helpful. The seal formed is hermetic and does not allow gas to escape the device nor air to enter the device. Referring now to Fig. 2B, device 202 is provided and illustrated. The configuration of device 2B is largely the same as that for device 200. Many of the parts are the same. Top occlusive layer 105 and bottom layer 106 are common to both devices and comprise the packaging in both instances. In this case, device 202 has a peripheral bead seal 203 disposed about the device and packaging instead of a multi- layered sealing approach described above. Bead seal 203 adheres to top packaging layer 105 and to bottom packaging layer 106. Bead 203 may also incorporate the area just along the outer edge of the adhesive layer. In the case of a bead seal, the act of removing the packaging layers may cause the seal to dislodge from any part of diffusion device 100 thereby ensuring the integrity adhesive layer 104 used to seal the device to an area of tissue to be treated.

One with skill in the art of forming seals will recognize there are several differing methods available for sealing packaging layers 105 and 106 of device 202. Press seal or heat seal techniques may be used. In mass production, a machine may be adapted to package the diffusion device including sealing the package. As described further above, the manufacture and packaging of the diffusion device may be undertaken relative to separate finite packages or to a packaged roll which contains the diffusion devices separable such as by perforation or the like.

Fig. 3 is an elevation view of a diffusion device 300 packaged according to an alternate embodiment. Device 300 is very similar to device 100 described further above. An occlusive layer 101 and diffusion layer 103 define the diffusion device along with an adhesive layer 104. In this embodiment, layer 101 is completely impermeable to any transfer of therapeutic agent or medium and therefore functions as part and parcel of the packaging to prevent escape of agent from the device. Layer 101 in this case is also impermeable to the ambient air and other environmental chemistries like dew, moisture, etc.

In this embodiment only one containment or packaging layer 301 is provided. Layer 301 resides directly adjacent to and underneath diffusion layer 103. Layer 301 may be sealed directly to adhesive layer 104 using a multi-layer adhesion where all contact surfaces have adhesive applied forming seal 302, or a bead sealing technique resulting in a bead seal 303. In this embodiment the volume between layer 301 and diffusion layer 103 may be fi811ed with the same therapeutic agent as is contained within the device. Also in this embodiment a user would remove layer 301 such as by peeling it off of the diffusion device when ready to use the device. Charging the volume between the packaging layer 301 and the diffusion layer of device 300 may aid to equalize pressure slowing or halting diffusion until the layer is removed.

Fig. 4A is a partial view of a packaged diffusion device with a multi-layered seal. Fig. 4B is a partial view of a packaged diffusion device with a peripheral bead seal. Fig. 4C is a partial view of a packaged diffusion device with the seal located more inward and away from the peripheral edge if the device. Referring now to Fig. 4A, a multi-layered seal 403 is applied between diffusion layer 402 and containment or packaging layer 401 of device 400. This embodiment is analogous to device 300 and seal 302 of Fig. 3. Packaging layer 401 would be removed before use and an adhesive layer analogous to adhesive layer 104 would secure the device to the targeted tissue area.

Referring now to Fig. 4B, layer 401 is sealed to device 400 using an adhesive bead 404 applied peripherally about the device. Referring now to Fig. 4C, an adhesive bead seal 405 is applied further into the device. This latter case is significant if the adhesive section of device 400 has multiple sections with one of them being permeable to the therapeutic agent.

Fig. 5 is an elevation view of a package diffusion device 500 according to a further embodiment of the invention. Device 500 includes an upper layer 501 that may not be absolutely impermeable to the therapeutic agent. Device 500 includes a diffusion layer 503. Packaging in this case comprises a lower packaging layer 502 and an upper packaging layer 504.

Packaging layer 504 is attached to layer 501 using common film adhesive techniques known to and available to the inventor. In this example layer 504 is sealed to layer 501 with a peripheral seal 506 to provide a hermetic seal. Layer 504 is adapted to be removed after diffusion device 500 is in use on a tissue area to allow the device (dressing) to breathe through the somewhat permeable layer 501. Packaging layer 502 is adapted to be sealed to device 500 adjacent to and beneath diffusion layer 503 using a peripheral seal 505 different types of which have been described further above. Packaging layer 502 should be impermeable to a therapeutic agent contained in device 500. Packaging layer 504 should also be impermeable to the therapeutic agent. For storage purposes it is also assumed at least that the sides of the package are also impermeable to the therapeutic agent thereby justifying the use of packaging layer 504 to "create" impermeability to a therapeutic agent stored within the device.

In one embodiment, layer 504 covers the entire upper surface of the whole device including the adhesive layer disposed peripherally about the device. In one embodiment which may include the embodiment just mentioned, layer 504 may include more than one sub-layer which may be independently peeled away from the covering layer. Such a sub-layer may be crafted to slightly overlap a preceding sublayer to enable easy peel-off of the sub-layer. Other layers may also comprise removable sub-layers without departing from the spirit and scope of the invention such as packaging layer 502 of this example and diffusion layer 503 of this example. In one embodiment layer 501 is a vapor transfer barrier to allow tissue to dry and to prevent wound maceration and is in a preferred embodiment mostly impermeable to the therapeutic agent contained in the device. Layer 502 is impermeable to the therapeutic gas and to the outside air and can be made from materials such as Polyvinylidene Chloride, or Polyurethane.

It will be apparent to one with skill in the art that the packaging of the invention may be provided using some or all of the mentioned features and components without departing from the spirit and scope of the present invention. It will also be apparent to the skilled artisan that the embodiments described above are exemplary of inventions that may have far greater scope than any of the singular descriptions. There may be many alterations made in the descriptions without departing from the spirit and scope of the present invention.