SELECTIVELY CONFIGURABLE WOUND DRESSING

Abstract

A wound dressing is selectively configurable for use in a pressure gradient wound therapy system and for use without a pressure gradient wound therapy system. The wound dressing can include a pressure distribution layer and a covering layer. The covering layer includes an indicia, the indicia denoting the optimal position in the covering layer to create an aperture to provide fluid communication between the pressure distribution layer and a source of non-atmospheric pressure.

Claims

1. A wound dressing selectively configurable for use in a pressure gradient wound therapy system and for use without a pressure gradient wound therapy system; the wound dressing comprising a pressure distribution layer and a covering layer; wherein the wound dressing comprises an indicia, the indicia being visible on an outside surface of the covering layer; the indicia denoting the optimal position in the covering layer to create an aperture to provide fluid communication between the pressure distribution layer and a source of non-atmospheric pressure.

2. A wound dressing according to claim 1 wherein the indicia is a mark.

3. A wound dressing according to claim 2 wherein the mark is formed of ink or dye.

4. A wound dressing according to any preceding claim wherein the indicia is printed.

5. A wound dressing according to claim 4 wherein the indicia is printed onto the covering layer.

6. A wound dressing according to claim 2 wherein the mark is formed by discoloration.

7. A wound dressing according to claim 6 wherein the indicia is laser marked.

8. A wound dressing according to any preceding claim wherein the indicia is located out of alignment with the centre of the dressing.

9. A wound dressing according to any preceding claim wherein the pressure distribution layer is provided adjacent to the cover layer, is gas and liquid permeable and moisture vapour permeable; wherein an adhesive layer is provided so as to form an adhesive border; wherein the indicia is located in a region of the covering layer within that defined by the adhesive border and located towards the periphery of the region of the covering layer inwards of the adhesive border; and comprising a release layer, the release layer being removable to reveal the adhesive border.

10. A wound dressing according to any preceding claim wherein in the configuration for use without a pressure gradient wound therapy system the region of the covering layer within that defined by the adhesive border is uninterrupted; and in the configuration for use with a pressure gradient wound therapy system the region of the covering layer within the adhesive border is interrupted by an opening, the opening being an aperture in the region of the indicia for connection to a source of non-atmospheric pressure.

11. A wound dressing according to any preceding claim which is a one-piece dressing in which the covering layer and the pressure distribution layer are formed as an integral item.

12. A wound dressing according to claim 11 including a dressing body comprising the pressure distribution layer and an absorbent material for contacting a wound, wherein the covering layer and the dressing body are formed as an integral item.

13. A wound dressing according to claim 12 wherein the dressing body is formed from a plurality of layers including a hydrocolloid material which gels in the presence of an exudate.

14. A wound dressing according to claim 12 or 13 wherein the absorbent body comprises one or more absorbent layer(s) and a silicone gel wound contact layer.

15. A wound dressing according to any of claims 12 to 14 wherein the absorbent material comprises gel forming fibres spun sodium carboxymethylcellulose fibres, chemically modified cellulosic fibres, alkyl sulphonate modified cellulosic fibres, pectin fibres, alginate fibres, chitosan fibres, hyaluronic acid fibres, or other polysaccharide fibres or fibres derived from gums.

16. A wound dressing according to claim 14 or claim 15 when dependent on claim 14, wherein the one or more absorbent layer(s) comprise an internal absorbent layer provided with fenestrations to aid the application of negative pressure to the wound and maintain the pathway for fluid from the wound, through the internal absorbent layer and a wound contact layer comprising gel-forming fibres is also provided.

17. A wound dressing according to any of claims 11 to 16 wherein the a one-piece dressing is provided in a sterile package.

18. A kit of parts including a selectively configurable wound dressing according to any preceding claim and at least one of: a. packaging indicating that the wound dressing is selectively configurable for use in a pressure gradient wound therapy system and without a pressure gradient wound therapy system; b. instructions instructing a user as to how to configure the wound dressing for use in a pressure gradient wound therapy system and for use without a pressure gradient wound therapy system; c. a piercing tool configured to pierce a covering layer of the wound dressing to produce an aperture therein and thereby configure the wound dressing for use in a pressure gradient wound therapy system; d. a source of non-atmospheric pressure; e. a port for connection to the covering layer of the wound dressing to connect the wound dressing to a source of non-atmospheric pressure; or f. tubing for connection between a wound dressing and a source of non-atmospheric pressure.

19. A kit of parts including a selectively configurable wound dressing, the wound dressing being configurable for use in a pressure gradient wound therapy system and without a pressure gradient wound therapy system; the kit further comprising at least one of: a. packaging indicating that the wound dressing is selectively configurable for use in a pressure gradient wound therapy system and without a pressure gradient wound therapy system; b. instructions instructing a user as to how to configure the wound dressing for use in a pressure gradient wound therapy system and for use without a pressure gradient wound therapy system; c. a piercing tool configured to pierce a covering layer of the wound dressing to produce an aperture therein and thereby configure the wound dressing for use in a pressure gradient wound therapy system; d. a source of non-atmospheric pressure; e. a port for connection to the covering layer of the wound dressing to connect the wound dressing to a source of non-atmospheric pressure; or f. tubing for connection between a wound dressing and a source of non-atmospheric pressure; wherein the wound dressing comprises a wound contact layer and a covering layer, the covering layer having a first surface facing the wound contact layer and defining a wound dressing cavity, and a second surface; wherein an indicia is visible on the second surface of the covering layer, the indicia denoting a suitable position in the covering layer to create an aperture to provide fluid communication between the wound dressing cavity and a source of non-atmospheric pressure.

20. A kit of parts according to claim 18 or 19 including at least one item selected from: (a) the packaging indicating that the wound dressing is selectively configurable for use in a pressure gradient wound therapy system and without a pressure gradient wound therapy system; and (b) the instructions instructing a user as to how to configure the wound dressing for use in a pressure gradient wound therapy system and for use without a pressure gradient wound therapy system.

21. A kit of parts according to any of claims 18 to 20 including at least one item selected from (c) the piercing tool configured to pierce a covering layer of the wound dressing to produce an aperture therein and thereby configure the wound dressing for use in a pressure gradient wound therapy system; (d) a source of non-atmospheric pressure; (e) the port for connection to the covering layer of the wound dressing to connect the wound dressing to a source of non-atmospheric pressure; and (f) the tubing for connection between a wound dressing and a source of non-atmospheric pressure.

22. A kit of parts according to any of claims 18 to 21 including (a) packaging in the form of cardboard packaging including printed information indicating that the wound dressing is selectively configurable for use in a pressure gradient wound therapy system and without a pressure gradient wound therapy system; wherein the packaging is sterile; and/or at least part of the packaging, or a sub-package is sterile.

23. A kit of parts according to any of claims 18 to 22 including (b) instructions instructing a user as to how to configure the wound dressing for use in a pressure gradient wound therapy system and for use without a pressure gradient wound therapy system printed on packaging or provided on an instruction sheet.

24. A kit of parts according to any of claims 18 to 23 including (c) a piercing tool configured to pierce a covering layer of the wound dressing to produce an aperture therein and thereby configure the wound dressing for use in a pressure gradient wound therapy system, the piercing tool comprising a scalpel.

25. A kit of parts according to any of claims 18 to 24 including (d) a source of non-atmospheric pressure which is a pump which provides a source of negative pressure

26. A kit of parts according to any of claims 18 to 25 including (e) a port for connection to the covering layer of the wound dressing to connect the wound dressing to a source of non-atmospheric pressure, the port being provided with an airway in the form of a transparent passageway securable to the outside of the cover layer at the proximal end of the conduit so as to surround the aperture in the cover layer from above and comprising a connector, at its distal end, for connecting the dressing to a source of non-atmospheric pressure

27. A kit of parts according to any of claims 18 to 26 including (f) tubing for connection between a wound dressing and a source of non-atmospheric pressure may be transparent tubing, the tubing formed from a resilient flexible plastics material.

28. A negative pressure wound therapy apparatus comprising a wound dressing according to any of claims 1 to 17 and/or a kit according to any of claims 18 to 27.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0071] In order that the invention may be more clearly understood one or more embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

[0072] FIG. 1 is a schematic representation of an embodiment of a wound dressing configured for use without a wound therapy apparatus;

[0073] FIG. 2 is a schematic representation of the wound dressing of FIG. 1 configured for use with a wound therapy apparatus;

[0074] FIG. 3 is an exploded view of another embodiment of a wound dressing configured for use without a wound therapy apparatus;

[0075] FIG. 4 is a cross-sectional view of the wound dressing illustrated in FIG. 3;

[0076] FIG. 5 is a cross-sectional view of a portion of the wound dressing illustrated in FIG. 3;

[0077] FIG. 6 is an exploded view of the embodiment of the wound dressing of FIG. 3 configured for use with a pressure gradient wound therapy apparatus

[0078] FIG. 7 is a side view of a piercing tool;

[0079] FIG. 8 is an exploded view of the wound dressing of FIG. 6 in use with a pressure gradient wound therapy apparatus;

[0080] FIG. 9 is a cross-sectional view of the wound dressing of FIG. 4 in use with a pressure gradient wound therapy apparatus;

[0081] FIG. 10 is a schematic representation of a wound exudate management system according to certain embodiments; and

[0082] FIG. 11 is a schematic representation of a kit of parts.

[0083] Embodiments disclosed herein relate to apparatus and methods of treating a wound both with and without reduced or positive pressure (typically negative pressure). Some embodiments including pump and wound dressing component. The wound dressings discussed are “one-piece” dressings incorporating both a covering layer and an absorbent body.

[0084] As disclosed herein the present invention may comprise a wound dressing; or a kit comprising the wound dressing and other apparatus for providing pressure gradient wound therapy to a wound.

[0085] As used herein the expression “wound” may include an injury to living tissue may be caused by a cut, blow, or other impact, typically one in which the skin is cut or broken. A wound may be a chronic or acute injury. Acute wounds occur as a result of surgery or trauma. They move through the stages of healing within a predicted timeframe. Chronic wounds typically begin as acute wounds. The acute wound can become a chronic wound when it does not follow the healing stages resulting in a lengthened recovery. It is believed that the transition from acute to chronic wound can be due to a patient being immuno compromised.

[0086] Chronic wounds may include for example: venous ulcers (such as those that occur in the legs), which account for the majority of chronic wounds and mostly affect the elderly, diabetic ulcers (for example, foot or ankle ulcers), peripheral arterial disease, pressure ulcers, or epidermolysis bullosa (EB).

[0087] Examples of other wounds include, but are not limited to, abdominal wounds or other large or incisional wounds (either as a result of surgery, trauma, stemiotomies, fasciotomies, or other conditions), dehisced wounds, acute wounds, chronic wounds, subacute and dehisced wounds, traumatic wounds (such as from orthopaedic trauma), flaps and skin grafts, lacerations, abrasions, contusions, burns, diabetic ulcers, pressure ulcers, stoma, surgical wounds, trauma and venous ulcers, broken bones or the like.

[0088] Wounds may also include a deep tissue injury. Deep tissue injury is a term proposed by the National Pressure Ulcer Advisory Panel (NPUAP) to describe a unique form of pressure ulcers. These ulcers have been described by clinicians for many years with terms such as purple pressure ulcers, ulcers that are likely to deteriorate and bruises on bony prominences.

[0089] The technology disclosed can be used on an acute or chronic wound.

[0090] Wounds are believed to be more susceptible to infection under the following circumstances. If the wounds are chronic wounds, or if an object which caused the wound was dirty or contained bacteria, or from a bite, or contains remnant or a whole object that caused the wound, or a wound that is large or deep, or jagged edges to the wound, or elderly, or chronic because by their nature a wound site is open; and/or if the patient has: diabetes type 1 or type 2, is elderly, or has a compromised immune system.

[0091] Pressure gradient wound therapy may also be useful for treating second- and third-degree burns, as well as being useful for laparotomy surgery i.e., a large incision through an abdominal wall to gain access into the abdominal cavity.

[0092] FIGS. 1 and 2 illustrates an embodiment of a wound dressing 1 in accordance with the invention in two different configurations.

[0093] In general, the invention relates to a wound dressing 1, which is selectively configurable for use without a pressure gradient wound therapy system or for use with a pressure gradient wound therapy system, e.g. negative pressure wound therapy.

[0094] As shown in FIG. 1, the wound dressing 1 includes an indicia 2 visible on the upper (outside) surface of a covering layer 3 of the dressing 1. The covering layer 3 has a raised central region 4, where it overlies a dressing body, which can include a pressure dispersion layer; an absorbent/superabsorbent layer/layers; and a wound-contact layer. The dressing 1 also has a border region 5, where it overlies an adhesive layer. A removable release layer (not shown) is provided on the underside.

[0095] The indicia 2 indicates where the dressing should be cut to form an aperture in order to configure the dressing for use with a pressure gradient wound therapy system; the dressing being configured for use without a pressure gradient wound therapy system unless/until an aperture is cut in the covering layer. In this embodiment, the indicia 2 is shown as a circle formed in dashed lines, arranged in the optimal position for connection of a source of non-atmospheric pressure. Obviously in other embodiments alternative shapes/signs could be used and of course the indicia need not be in dashed lines.

[0096] As illustrated in FIG. 1, the wound dressing is configured for use without a pressure gradient wound therapy system. To use the wound dressing 1 without a pressure gradient wound therapy system, the release layer is simply removed and the dressing applied in the same way as an ordinary wound dressing. It will be noted that the entire raised central region 4 of the covering layer 3 is a continuous unbroken membrane, uninterrupted and closed, so that the wound (within the region defined by the adhesive border) is in a sealed environment, restricting/preventing bacteria/microbes entering the wound and causing infection.

[0097] FIG. 2 shows the wound dressing 1 of FIG. 1 configured for use with a pressure gradient wound therapy system. Here, a user has cut through the cover layer 3 using a bladed instrument, such as a scalpel, in the region of the indicia 2, to form an aperture 6 in the wound dressing 1 (so that the central region 4 is no longer closed/uninterrupted). With the wound dressing 1 now configured for use with a pressure gradient therapy system, a source of non-atmospheric, e.g. negative, pressure can be connected to the aperture 6 to aid the wound-healing process.

[0098] For example, a port (not shown in FIG. 1 or 2) can be adhered to the wound dressing 1, such that a conduit through the port is aligned with the aperture 6; the port can be connected via tubing (also not shown in FIGS. 1 and 2) to a pump (also not shown in FIGS. 1 and 2) producing negative pressure.

[0099] With additional reference to FIGS. 3-4, illustrated therein is a schematic of another exemplary wound dressing 300.

[0100] The illustrated wound dressing 300 generally includes a covering layer 310 and an adhesive layer 320 for adhering the wound dressing 300 adjacent the wound. In certain embodiments, the wound dressing 300 further comprises a wound contact layer 330 for contacting the wound, a pressure dispersion layer 340, a plurality of absorbent material layers 350 disposed between the wound contact layer 330 and the pressure dispersion layer 340.

[0101] The covering layer 310 has a first surface 311 and a second surface 312, and the first surface 311 is adjacent, and in contact with, the pressure dispersion layer 340 and the adhesive layer 320. The covering layer 310 defines a cavity in which the pressure dispersion layer 340 is arranged. In certain embodiments, the covering layer 310 is formed of a polyurethane film. The covering layer 310 comprises indicia 314 again in the form of a dashed circle, arranged in the optimal position for connection to a source of negative pressure.

[0102] The polyurethane film is transparent, so the indicia can be printed on the inside first surface 311 or the outside, second, surface 312 of the film layer 310. In another embodiment it is printed on the layer beneath the transparent covering layer 310, so as to be visible on the outside second surface 312.

[0103] The adhesive layer 320 generally defines a border about an opening 322 for receiving the wound. In certain embodiments, the adhesive layer 320 comprises a silicone adhesive. In certain embodiments, the adhesive layer 320 may be perforated.

[0104] The wound contact layer 330 overlaps the border defined by the adhesive layer 320, and is configured to contact the wound via the opening 322. In certain embodiments, the wound contact layer 330 may comprise Medicel™. In certain embodiments, the wound contact layer 330 comprises carboxymethylated cellulose fibers. In certain embodiments, the wound contact layer 330 may comprise HYDROFIBER®. In certain embodiments, the wound contact layer 330 may be reinforced, for example via nylon stitching. Thus, the wound contact layer 330 may comprise reinforcing nylon stitching 332.

[0105] The pressure dispersion layer 340 is adjacent and in contact with the first surface 311 of the cover layer 310. In certain embodiments, the pressure dispersion layer 340 may be provided as a polyester foam layer. In certain embodiments, the pressure dispersion layer 340 comprises reticulated foam.

[0106] The absorbent material layers 350 are positioned between the wound contact layer 330 and the pressure dispersion layer 340. The wound dressing 300 may, for example, comprise eight absorbent material layers 350. In certain embodiments, one or more of the absorbent material layers 350 may comprise carboxymethylated cellulose fibers. In certain embodiments, one or more of the absorbent material layers 350 may comprise Medicel™. In certain embodiments, one or more of the absorbent material layers 350 may comprise HYDROFIBER®. In certain embodiments, one or more of the absorbent material layers 350 further comprises fenestrations 352.

[0107] In certain embodiments, as shown in FIG. 4, the wound dressing 300 may include an additional layer 370 between the pressure dispersion layer 330 and the uppermost absorbent layer 350. The additional layer 370 may, for example, be formed of thermoplastic. In certain embodiments, the additional layer 370 may be provided as a thermoplastic spun lace layer. In certain embodiments, the wound dressing 300 may further comprise a nonwoven spun lace layer 372 connected to the wound contact layer 330. In certain embodiments, an envelope structure 374 is formed by joining peripheral portions 373 of the thermoplastic spun lace layer 370 and the nonwoven spun lace layer 372 such that the plurality of absorbent material layers 350 are disposed substantially within an interior cavity 375 of the envelope structure 374, for example as illustrated in FIG. 5. In certain embodiments, the absorbent material layers 350 are disposed within the interior cavity 375 of the envelope structure 374.

[0108] In certain embodiments, the wound dressing 300 may include a further layer 380 positioned between the wound contact layer 330 and the lowermost absorbent layer 350. The further layer 380 may, for example, be a polyester/viscose layer.

[0109] As is well known, and therefore not shown, the wound dressing 300 may be provided with a removable release layer on the underside, covering the adhesive layer 320 and the underside of the wound contact layer 330; and it may be individually packaged within a sterile package.

[0110] As illustrated in FIGS. 3-5, the wound dressing is configured for use without a pressure gradient wound therapy system. To use the wound dressing 300 without a pressure gradient wound therapy system, it is simply removed from its sterile packaging, then the release layer is simply removed and the dressing applied in the same way as an ordinary wound dressing. Again, it will be noted that in this configuration the entire region of the covering layer 310 within the peripheral adhesive border defined by the layer 320 is uninterrupted and closed, sealing the wound against microbes/bacteria that could cause infection.

[0111] FIG. 6 shows the wound dressing 1 of FIGS. 3-5 configured for use with a pressure gradient wound therapy system. Here, a user has cut through the cover layer 310 using a bladed instrument, such as the scalpel shown in FIG. 7, in the region of the indicia 314, to form an aperture 306 in the wound dressing 300. As such, the region of the covering layer 310 within the peripheral adhesive border defined by the layer 320 is now interrupted by the aperture 306, which forms an opening.

[0112] Next, and as shown in FIGS. 8 and 9, a port 307 is adhered to the outside, second surface 312 of the cover layer 310. An adhesive ring 366 attaches the port 307 to form a seal between one end 361 of the tube 360 and the port 307. The opposite end 362 of the tube 360 may be connected with a fitting such as a Luer lock 364.

[0113] With additional reference to FIG. 10, illustrated therein is a pressure gradient wound therapy system 400 according to certain embodiments. The pressure gradient wound therapy system 400 comprises a pump 410 for generating negative pressure, a wound dressing 420 (which may be the wound dressing 1 or 300 described above) for covering and protecting a wound, an inline filter 430, a first pressure tube 440 having a first interior lumen 442, a second pressure tube 450 having a second interior lumen 452, and a flexible connector 460. The first pressure tube 440 is disposed between the pump 410 and the inline filter 430. The second pressure tube 450 is disposed between the inline filter 430 and the flexible connector 460. The flexible connector 460 is disposed between the second pressure tube 450 and the wound dressing 420 such that the pump 410 and the wound dressing 420 are in fluid communication via the interior lumens 442, 452.

[0114] The wound dressings 1, 300, 420 may be provided in kits. As illustrated schematically in FIG. 11, the kits can comprise one or preferably more than one of the selectively configurable wound dressings 1, 300, 420 and at least one of the following items, all of which are included in this exemplary kit:

[0115] (a) packaging 500 indicating that the wound dressing is selectively configurable for use in a pressure gradient wound therapy system and without a pressure gradient wound therapy system. In this example the packaging is a cardboard box, printed with instructions 501 for use.

[0116] (b) instructions instructing a user as to how to configure the wound dressing for use in a pressure gradient wound therapy system and for use without a pressure gradient wound therapy system. In this example, the instructions are printed on a leaflet 502 included in the box.

[0117] (c) a piercing tool configured to pierce a covering layer of the wound dressing to produce an aperture therein and thereby configure the wound dressing for use in a pressure gradient wound therapy system. In this embodiment, the piercing tool takes the form of the scalpel 20.

[0118] (d) a source of non-atmospheric pressure. In this embodiment, the source of non-atmospheric pressure is the pump 410.

[0119] (e) a port for connection to the covering layer of the wound dressing to connect the wound dressing to a source of non-atmospheric pressure. In this embodiment the port is the port 307 described above.

[0120] (f) tubing for connection between a wound dressing and a source of non-atmospheric pressure. In this embodiment tubing 440 described above is included.

[0121] For use where it is envisioned that a wound will initially require treatment with a pressure gradient wound therapy system, the kit may comprise one or more preferably a plurality of, dressings 1/300/420 and one or more of items c, d, e and f, for example all of items c, d, e and f, and optionally items a and/or b as well. As such, the user can be provided with all the equipment required to use the wound dressings 1/300/420 with a pressure gradient wound therapy system.

[0122] In order to use such a kit, the user (e.g. a patient or HCP) can cut an aperture in a dressing 1/30/420 in the region of the indicia, optionally using the piercing tool 20; attach a port 307 thereto, around the aperture, and in fluid communication therewith; attach one end of the tubing 440 to the port 307 and the other to the pump 410 and run the pump 440 to provide non-atmospheric (e.g. negative) pressure to the wound.

[0123] Then, if/when the pressure gradient therapy is no longer necessary, the user can use up any remaining wound dressings 1/300/420 without the pressure gradient wound therapy system, by applying them to the wound without cutting an aperture in the dressings 1/300/420 in the region of the indicia, so as to maintain a sealed environment around the wound.

[0124] On the other hand, for use where it is envisioned that a wound does not require treatment with a pressure gradient wound therapy system (and most preferably where it is envisioned that a wound does not require treatment with a pressure gradient wound therapy system, but it is considered that there is a risk that the wound will not heal well without a pressure gradient so in future, pressure gradient wound therapy might be useful), the kit may comprise one, or more preferably a plurality of selectively configurable dressings 1/300/420 and one or both of items a and b. As such, the user has instructions on how to use the dressings without a pressure gradient wound therapy system and can simply apply a dressing 1/300/420 to the wound in the configuration for use without a pressure gradient wound therapy system. Thus the user can follow the instructions by removing the release layer and applying the dressing to the wound without cutting an aperture in the region of the indicia 2, 314, so that the cover layer is uninterrupted and closed within the adhesive border, and the is wound sealed against bacteria/microbes.

[0125] Then, should it be determined that the wound would benefit from pressure gradient therapy (e.g. negative pressure), the user can follow the instructions from the packaging/instructions, to cut a hole in the covering layer 3/310 in the region of the indicia 2/314 and apply a pressure gradient wound therapy system as outlined above (sourced for example from another kit), without having to first remove the dressing 1/300/420 (which can present an opportunity for infection).

[0126] Conditional language, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, and/or steps. Thus, such conditional language is not generally intended to imply that features, elements, and/or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements, and/or steps are included or are to be performed in any particular embodiment.

[0127] Each of the documents referred to above is incorporated herein by reference. Except in Examples, or where otherwise explicitly indicated, all numerical quantities in this description specifying amounts of materials, device dimension, and the like, are to be understood as modified by the word “about.”

[0128] Unless otherwise indicated, each chemical or composition referred to herein should be interpreted as being a commercial grade material which may contain the isomers, by-products, derivatives, and other such materials which are normally understood to be present in the commercial grade.

[0129] The one or more embodiments are described above by way of example only. Many variations are possible without departing from the scope of protection afforded by the appended claims.