BACKGROUND

I00O1J The present disclosure relates to odor barrier films, and more particularly to biodegradable odor barrier films for medical uses such as ostomy, continence, and bowel management applications.

|0002| Gas and odor barrier films are known and widel used in the medical field. Many such films have a barrier layer that contains chlorine; other barrier layers are chlorine-free. Chlorine-containing barrier layers use, for example, copolymers of viaylidene chloride vinyl chloride (VDC-VC) copolymers) and vinylidene chloride methyl acrylate copolymer (VDC-MA copolymers). These chlorine^contadning films have exceptionally high malodor«causing compound barrier properties and are typically not adversely affected by the presence of moisture. One drawback to the use of chlorine-containing compounds is that these compounds, generally, present environmental issues in disposal, for example, incineration of materials te use. Another drawback is that specialized equipment is required to process these materials due to the corrosive nature of the chlorine compounds.

0OO3| Thus, barrier films including a barrier layer formed of chlorine- free vinyl alcohol based polymers, such as ethylene vinyl alcohol (EVOH) copolymers and polyvinyl alcohol) (PVOH) were developed. However, ostomy products and other applications relating to storing and transporting bodily waste are highly demanding and typically subject materials used in such products to high levels of moisture. Further, it is extremely important that the odor barrier properties of the material are, and remain high throughout their useful life. Unfortunately , these barrier films including barrier layers formed of vinyl alcohol based polymers have been found to have reduced barrier performance in the presence of humidity .

[ 0041 Farther, mere are multilayer barrier films including a barrier layer comprising a polyamide. For example, Giori, U.S. Patent No. 7,270,860, which is assigned to the Applicant of the present application and incorporated herein by reference, discloses a fiv layer film including an odor barrier layer formed from a blend of amorphous polyamide and anhydride-modified olefin polymer. WO

2011/056861, which is also assigned to the Applicant of the present application and incorporated herein by reference, also discloses a multilayer film including an odor 2 barrier layer comprising amorphous polyamide. Such multilayer films are chlorine free, and provide improved moisture and odor barrier characteristics, tear strength, comfort and ''quietness' ^* when compared to other chlorine free films. However, although they are more environment friendly than the chlorine containing films, these barrier films are not biodegradable.

10005) Efforts have been made lo develop biodegradable ostomy, continence, and bowel management appliances. However, biodegradable films have been insufficient for providing odor barrier properties in the.se applications. Thus, partially biodegradable appliances, such as flushable ostomy pouch products including an inner pouch formed from a biodegradable film and an outer pouch formed of a conventional non-biodegradable odor barrier film, have been developed. For example, a "pouch-in-pouch" ostomy appliance includes an inner pouch made from a biodegradable film, which can be flushed in a toilet, and an outer pouch made from a conventional non-biodegradable barrier film, which provides odor barrier properties. However, such partially biodegradable appliances are more complicated to manufacture, thus, more expensive, and typically re uire additional steps in use, which make them less desirable to users.

(0006) Accordingly, there is a need for an odor barrier 111m that JS biodegradable and has sufficient odor barrier and physical properties for me in ostomy, continence, and bowl management products.

BRIEF SUMMARY

f0007) Biodegradable odor barrier films and biodegradable odor barrier tubes for ostomy, continence and bowel management applications are provided according to various embodiments. Such films and tubes include a barrier layer formed essentially from poly glycol ic acid (PGA) to provide excellent mechanical and odor barrier properties along with biodegradability desired in ostomy, continence, and bowel management applications.

[0008] in one aspect, a biodegradable odor barrier film for ostomy, continence and bowel management applications is provided. The biodegradable odor barrier film includes a barrier layer comprising a biodegradable resin. The barrier layer has a biodegradability that meets the requirements of ASTM D6 00, EN 13432 or 1S014855. Further, the biodegradable odor barrier film has a dimethyl disulfide 3

(DMDS) breakrarough tim greater than about 200 ratnuies when tested according to the modified Test: Operations Procedure (TOP) 8*2-501 as provided in this disclosure;

|0009| In one embodiment, the barrier layer comprises polyglycolic acid (PGA) in a concentration greater than about 90 percent by weight (% wt). For example, the barrier layer may be formed from a blend comprising about 90% wt. to about 99% wt. of PGA and a polymeric chain extender. In another example, the barrier layer may be formed of about 100% wt. PGA.

jOOlO] The barrier layer has a first side and a second side. n some embodiments, the biodegradable odor barrie film may include a first outer layer disposed on the first side, and a second outer layer disposed on the second side, such that the barrier layer may be sandwiched between the first and second outer layers. The first and second outer layers may also be biodegradable, such that the

biodegradable odor barrier film has a biodegradability that meets the requirements of AST D6400, EN13432 or ISOI4855.

{0011] The first and second outer layers may include a biodegradable material selected from the group consisting of starch, starch blends, pol vinyl alcohol, efhylene-vtnyl alcohol copolymer, cellulose derivatives, soy protein,

polycaprolactone, po!ylacac acid, copolyester, polyhydroxyaikanoates, and polybutylene succinate. For example, the first and second outer layers may comprise at leasi ?0%wt. of a copolyester based on ierephthalic acid, adipic acid, and 1 ,4- btuanediol. The first and second outer layers may also include an antiblock agent, a slip agent, and/or a blowing agent.

f00l2] In some embodiments, the biodegradable odor barrier film further includes first and second tie layers disposed between the barrier layer, and the first and second outer layers, respectively, in which each tie layer contacts a respective side of the barrier layer. The tie layers may be formed from a maleated polyolefin or an epoxidized polyolefin.

10013] In another embodiment, a thickness of the barri er layer ma make up about 3% to about 20% of a total thickness of the biodegradable odor barrier film. For example, a total thickness of the film may be between about ΤΟμτη and about Ι,ΟΟΟμιη, in which a thickness of the barrier layer may be between about (>.5μιη and about 50«m.

|001 ) A bowel management tube may be formed iising any of the biodegradable odor barrier films discussed above, in which the biodegradable odor 4 barrier film has a tola! ttoekness between about 500um and Ι,ΟΟΟμηι, and the barrier layer has a thickness between about 2pm and about 50um.

fOOlSj In another aspect, an ostomy poach comprising a biodegradable odor barrier film is provided. The ostomy pouch includes a first side wall and a second side wall The first and second side walls are formed from a biodegradable odor barrier film having a biodegradability mat meets the requirements of ASTM D6400, EN13432 or IS014855, and a dimethyl disulfide (DMDS) breakthrough time greater than about 200 minutes when tested according to the modified TOP 8-2-50. The ostomy pouch also includes a stoma-receiving opening on the first side wail.

|0016] In some embodiments, the first and second walls ma be formed of a biodegradable odor barrier film, which includes a barrier layer comprising polygjycolic acid <PGA) in a concentration greater than about 90 percent by weight (% wt.) For example, the barrier layer may be formed from a blend comprising about 90% wt. to about 99% wt. of PGA and a polymeric chain extender. In another example, the barrier layer may be formed of about 100% wt PGA

|8ftl7J in some embodiments, the biodegradable odor barrier film may include a first outer layer and a second outer layer disposed on each side of the barrier layer, such that the barrier layer may be sandwiched between the first and second outer layers. The first and second outer layers may also be biodegradable, such that the biodegradable odor barrier film has a biodegradability that meets the requirements of ASTM D6400, ENI3432 or IS014855. In such embodiments, the first and second outer layers may include at least 70%wt. of a copolyester based on terephthaiic acid, adipic acid, and 1,4-butanediol. The first and second outer layers may also include an antiblock agent, a slip agent, and/or a blowing agent.

|0018] The ostomy pouch according to any of the embodiments discussed above may include at least one nonwoven layer attached on one or both of the first and second side walls. The nonwoven layer may also be formed from a biodegradable material.

|0019] Other aspects,, objectives and advantages will become more apparent from the Ml win detailed description when taken in conjunction with th accompany ing drawings. 5

BRIEF DESCRIPTION OF THE DRAWINGS

{0020] The benefits and advantages of the resent embodiments will become more readily apparent to those of ordinar skill in the relevant art after reviewing the following detailed description; and accompanying drawings, wherein:

|00211 FIG. 1 is a cross-sectional illustration of a three-layer biodegradable film in accordance with an embodiment of the present disclosure;

{00221 FIG. 2 is a cross-sectional illustratio of a five-layer biodegradable film in accordance with another embodiment;

10023] FIG. 3 is a cross-sectional illustration of an exemplary ostomy pouch including a biodegradable film; and

0024J FIG.4 is an illustration of an exemplary bowel management tube made from a biodegradable material.

DETAILED DESCRIPTION

{0025] While the present disclosure is susceptible o f embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification and is not intended to limit the disclosure to the specific embodiment illustrated.

{0026] Referring now to the figures and in particular to FIG. I„ there is shown a biodegradable multilayer film 10 according to an embodiment The film 10 may be a th ee-layer film including a barrier layer 12 comprising a biodegradable resin that can be composted to carbon dioxide, water and biomass under aerobic conditions in municipal and industrial aerobic composting lacilities, tor example, polyglycolic acid (PGA). The film 10 also may include first and second outer layers 14, 16, in which the barrier layer 12 may be sandwiched between the outer layers 14, 16.

{0027] The barrier layer 12 may be the thinnest layer of the film 10 making up less man about 20% of the total thickness, for example* between about 3% and .15% of the total thickness. The barrier layer 12 has biodegradability that satisfies th test protocols of ASTM D6400, 1N13432, or 18014855. The barrier layer 12 is also substantially impermeable to malodor causing compounds typically encountered in ostomy pouches. Such malodor causing compounds can include sulfnr containing compounds and indoles. Examples of sulfur-con taining compounds include dimethyl 6 disulfide, dimethyl trisulfide, diethyl disulfide, hydrogen sulfide and methyl mercapian. Ex amples of indoles, and other malodor causing compounds include 3- methyl indole and methanethiol. Other compounds will be recognised by those skilled in the art. Further, the barrier layer imparts tear strength to the film.

|9928] Polyglycolic acid (PGA) resin is particularly suitable for the barrier layer. PGA has superior oxygen, carbon dioxide, and water vapor barrier properties. Further, the inventors of the present application have discovered that PGA also has excellent odor barrier properties, which are only minimally affected by moisture content, which makes ate PGA particularly suitable for ostomy, continence and bowl management applications. The PGA resin can have similar biodegradability as cellulose, and can typically degrade into carbon dioxide and water in compost within about one month.

|9929J A first outer layer 14 may be disposed on one side of the barrier layer 12, and a second outer layer 16 may he disposed on the other side of the barrier layer 12. Each of the outer layers 14 _t 16 maybe substantially biodegradable and may comprise one or more biodegradable material ihat is compatible with the PGA resin in the barrier layer 12. The materials for the outer layers 14, 16 are carefully selected to provide desired Sim characteristics for a particular application, for example, biodegradability, water solubility, and heat scalability. Suitable biodegradable materials for the outer layers 14, 16, which are compatible with PGA resin include, but are not limited to polycaprolactone (PCL), polylactic acid (PLA), copolyester, polyhydroxyalkanoates (PHAs), and polybutylene succinate (PBS).

19930] For ostomy pouch applications, at least one of the outer layers may be formed of a biodegradable material having good sealing characteristics, lor example, heat scalability, suitable for forming a pouch, while the other outer layer may be formed of a biodegradable material, which can provide comfort against a user's skin.

]0031] In one embodiment, the barrier layer 12 is formed irora blend comprising at least 90% wt. PGA resin, for example about 99% wt, PGA tejsin. Each, of the outer layers 14, 16 may be formed fiom a blend comprising a biodegradable polymeric material compatible with the PGA resin, for example, an aliphatic-aromatic copolyester resin, such as copolyester based on terephthalie acid, adipic acid, 1,4- bulanedioi and modular units. Such copolyester resins provide good flexibility and 7 toughness^ and are reasonably low cost, which make them suitable tor ostom , eoniinenee, and bowel management applications.

|0032| The blend for the outer layers 14, 16 ma also include an antiblock agent, such as CatX¼ and talc, and/or a slip agent, which can miproye extrudability and reduce the risk of the outer layers 14, 16 sticking to a chill roller. Further, the blend ma also include a blowing agent. In one embodiment, the barrier layer 12 and outer layers 14, 16 are coextruded.

|0033] In other embodiments, the biodegradable multilayer film can include more tha three layers or less than three layers. For example, two-layer lite may include a barrier layer formed essentially of PGA resi and an outer layer formed of a biodegradable material compatible with the PGA resin, in some embodiments, a biodegradable film may be a single layer film comprising PGA resin.

10034) FIG. 2 shows another embodiment of a biodegradable multilayer film 1 0. The film 00 may be a five-layer film including a barrier layer 1 2, tie layers 108, 110, and outer layers 104, 106. Similar to the biodegradable film 10 of FIG. 1, the barrier layer 1 2 may be formed essentially from a biodegradable material, preferably PGA resin. The outer layers 104, 106 are also formed essentially from one or more biodegradable materials.

003S) As shown in FIG. 2, on either side of the barrier layer 102 may be a tie layer 1 8, 110. Each of the tie layers 108, 110 may be formed from a material that is compatible with the PGA resin in the barrier layer 102. The tie layers 108, 110 facilitate adhesion of the barrier layer 102 to the remainder of the film structure. Outer layers 104, 6 are arranged adjacent to the tie layers 108, 0, respectively.

|9936] Suitable tie layer materials that are compatible with PGA resin include, but are not limited to, resins with maleic anhydride, such as maleated poiyolefins (e.g. resins available under trade name Bynel* from DuPont), or resins including epoxy functionality, such as epox dked poiyolefins (e.g. resins available under trade name Lotader^ from Arkema).

{0037] In other embodiments, a biodegradable multilayer film can have various kyer structures to provide desired film, characteristics few ostomy* continence, or bowel management applications. For example, a biodegradable film for ostomy pouch applications may include seven layers with ABCDCBA structure, in which A represents skin/seal layers, B represents inner layers, C represents tie layers, and D represents a barrier layer formed of PGA resin. Other examples include a six- 8 layer film including a harrier laye , two tie layers, an inner layer, nd two skin layers (i.e. ABCOCA), and a five-layer film including a barrier layer, two tie layers and two outer layers (i.e. ACDCA, BCDCB or ACDCB). The biodegradable multilayer films according to various embodiments include a barrier layer formed essentiall of a biodegradable material, such as PGA resin, and other layers which are substantially biodegradable.

{0038] FIG. 3 is a cross-sectional illustration of a one-piece ostom pouch 20 made using a biodegradable odor barrier film comprising PGA resin. The ostomy pouch 20 generally includes a pouch 22 and a skirt barrier 24. The pouch 22 includes first and second opposing walls 26, 28, which are sealed around peripheral edges 30 thereof to define a cavity 32 for collecting body waste. Each of the walls 26, 28 may be formed of a biodegradable odor barrier film comprising PGA resin, such as the three-layer film 10 of FIG. I or ihe five-layer film 100 of FIG.2. The pouch 22 also includes a first nonwoven layer 34 attached to the first wall 26, and a second nonwoven layer 36 attached to the second wall 28. The nonwoven layers 34, 36 are attached to the respective walls 26, 28 via heat sealing or an adhesive. The nonwoven layers 34, 36 may be formed from one or more biodegradable materials, and thus, substantially biodegradable, in other embodiments, the ostomy pouch 20 ma no include a nonwoven layer or include only one nonwoven layer.

10039] FIG. 4 is a bowel management tube 40 comprising a biodegradable odor barrier layer comprising PGA resin. The bowel management tube 40 can be made using a biodegradable odor barrier film according to various embodiments in the present disclosure. For example, the bowel management tube 40 can be made using the three-layer film 10 of FIG. 1, or the five-layer film 100 of FIG . 2. In other embodiments, the bowel management tube 40 can be extruded as a single layer tube comprising PGA resin. Further, the bowel management tube 40 may be coextruded as a multilayer tubing including an odor barrier layer comprising PGA resin, and inner and outer layers comprising a biodegradable material similar to the above described biodegradable film embodiments.

$am,pje Multilayer Biod g adable Films

| 04OJ Four different three-layer film samples including a barrier layer formed essentially from PGA resin were prepared. Each of the film samples includes a barrier layer and two outer layers as shown in FIG. I . 9

[0041] Sample 303-2 had a total thickness of about 43 μηι. The barrier layer 12 had a thickness of about 4μηι and comprised about 99% wt. of PGA

(Kuredux ^® PGA B35 from Kureha) and about 1% wt. of an oligomeric chain extender based on multiple epoxy functional groups (Joncryl ^® ADR 4368 from BASF). Each of the outer layers 14, 16 had a thickness of about 19.5μπι and was formed from a blend comprising biodegradable polymeric materials. The blend included about 78.5% wt. of Ecoflex ^® F Blend C1200 from BASF (copolyester based on terephthalic acid, adipic acid, and 1, 4-butanediol), about 20% wt of Ecoflex ^® Batch AB1 from BASF (antiblock agent masterbatch including about 60% wt. of fine chalk and about 40% wt. of Ecoflex ^® F Blend C1200), and about 1.5% wt. of Ecoflex ^® Batch SL1 from BASF (slip agent masterbatch including about 10% wt. of erucamide and about 90% wt. of Ecoflex ^® F Blend C1200.)

[0042] Sample 303-3 had a total thickness of about 69μπι. The barrier layer 12 had a thickness of about 4μιη and comprised about 99% wt. of PGA

(Kuredux ^® PGA B35 from Kureha) and about 1% wt. of an oligomeric chain extender based on multiple epoxy functional groups (Joncryl ^® ADR 4368 from BASF). Each of the outer layers 14, 16 had a thickness of about 32.5μπι and was formed of the same blend used for the outer layers of Sample 303-2.

[0043] Sample 303-4 had a total thickness of about 56μιη. The barrier layer 12 had a thickness of about 6μιη and comprised about 99% wt. of PGA

(Kuredux ^® PGA B35 from Kureha) and about 1% wt. of an oligomeric chain extender based on multiple epoxy functional groups (Joncryl ^® ADR 4368 from BASF). Each of the outer layers 14, 16 had a thickness of about 25μπι and was formed of the same blend used for the outer layers of Sample 303-2.

[0044] Sample 303-5 had a total thickness of about 58μιη. The barrier layer 12 had a thickness of about 3μιη and comprised about 99% wt. of PGA

(Kuredux ^® PGA B35 from Kureha) and about 1% wt. of an oligomeric chain extender based on multiple epoxy functional groups (Joncryl ^® ADR 4368 from BASF). Each of the outer layers 14, 16 had a thickness of about 27.5μπι and was formed of the same blend used for the outer layers of Sample 303-2. The sample films are summarized in Table 1

TABLE 1 - Sample Biodegradable Odor Barrier Films

Sample | Outer Layer | Barrier Layer | Outer layer

[0045] The film samples and a control film sample were tested for tensile properties in both the machine direction (MD) and the transverse direction (TD). The control film sample was prepared using a multilayer odor barrier film, which is commercially used in some ostomy pouches. The control film sample had a total thickness of about 76 μηι, and included an odor barrier layer having a thickness of about 5 μπι and comprising vinylidene chloride-methyl acrylate copolymer.

[0046] The samples were also tested for odor barrier properties.

Following a modified version of Test Operations Procedure (TOP) 8-2-501 for Permeation and Penetration of Air-Permeable, Semi-permeable, and Impermeable Materials with Chemical Agents or Simulants, a time for dimethyl disulfide (DMDS) to permeate through a film sample was measured. In this test, 15% wt DMDS in isopropyl myristate solvent was used as a challenging gas with nitrogen carrier gas. The flow rate of the carrier gas across a sample film was 125 cc/min and the temperature in the test chamber was 38±2°C. A breakthrough time, which is a time for the DMDS challenging gas to permeate through a sample film and reach 1 part per million (ppm) concentration, was measured using gas chromatography (GC). The test results of the samples and control film are summarized in Table 2, below.

TABLE 2 - Tensile and Odor Barrier Test Results

[0047] As shown in Table 2, the sample biodegradable films including a barrier layer comprising PGA provided significantly improved odor barrier properties when compared to the control film sample. Further, the sample biodegradable films also had better or comparable tensile properties as the control film sample. Thus, the sample biodegradable films can be used to make durable ostomy appliances having excellent odor barrier properties.

[0048] In the present disclosure, all percentages of constituents are by weight, unless otherwise indicated. In the present disclosure, the words "a" or "an" are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular. All of the

concentrations noted herein as percentage are percent by weight unless otherwise noted.

[0049] From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims.