Skin compatible silicone-based adhesive compositions for securing medical devices to mammalian skin

Abstract

An adhesive composition including a polysiloxane adhesive. The adhesive composition may include a reinforcing component. The adhesive composition may include a plasticizing component. The adhesive composition may include an absorbing component.

Description

SKIN COMPATIBLE SILICONE-BASED ADHESIVE COMPOSITIONS FOR SECURING MEDICAL DEVICES TO MAMMALIAN SKIN

[0001] FIELD

[0002] The disclosure relates to skin compatible silicone-based pressure sensitive adhesive compositions for securing medical devices to mammalian skin. The compositions may comprise composite mixtures of silicone pressure sensitive adhesive and additives intended to provide a balance of properties beneficial to end-user experience and skin health, including, but not limited to, security, atraumatic adhesion, moisture capture, moisture transmission, and gas transmission (e.g., oxygen). These compositions are primarily suited as skin adhesives for ostomy care but may also be adapted for use in general skin care, for example for use in the treatment of wounds or burns.

[0003] BACKGROUND

[0004] In healthcare settings, adhesive compositions may be utilized in the form of an ostomy device ‘wafer’ or ‘baseplate’ by persons with a stoma, herein referred to as ostomates, to secure output collection devices directly to the skin. The adhesive composition is one of the key features of an ostomy appliance, as the end-user is reliant on the adhesive to form a secure interface with the skin to affix the collection device and prevent leakage. Lack of a secure interface between skin and adhesive can have a detrimental impact on the daily quality of life of ostomates, impeding or even preventing them from undertaking routine tasks with confidence. Furthermore, as the adhesive composition interfaces with skin continuously whilst an ostomates stoma is present, peristomal skin health is inherently dependent on features of the adhesive, such as atraumatic adhesion, moisture capture, moisture transmission, and gas transmission (e.g., oxygen).

[0005] In the United States, there are up to 1 ,000,000 ostomates living with a stoma, and approximately 100,000 new stomas are formed yearly (J. Burgess-Stocks et al., Ostomy and continent diversion patient bill of rights: research1Ref: H16904WO / MZCvalidation of standards of care. The Journal of Wound, Ostomy and Continence Nursing, 2022, 49, 251-260). In the United Kingdom by comparison, there are up to 205,000 ostomates, and somewhere in the region of 13,500 to 21,000 stoma surgeries are performed on an annual basis (W. Osborne et al., Prevalence of leakage and its negative impact on quality of life in people living with a stoma in the UK. British Journal of Nursing, 2022, 31, S24-S38). Around 80 percent of the ostomate population experience peristomal skin complications (S. Meisner & L. Balleby, Peristomal skin complications. Seminars in Colon and Rectal Surgery, 2008, 19, 146-150). Preventing peristomal skin complications is critical to effective ostomy care, and as such, there is a clear requirement for skin adhesive compositions that mitigate or avert adverse peristomal skin events. S. Meisner & L. Balleby cite leakage of output from the stoma as the primary cause of peristomal skin complications; the corrosive nature of effluent and its subsequent contact with the skin can lead to the development of severe irritation and infection. S. Meisner & L. Balleby state that another cause of peristomal skin complications includes frequent mechanical stripping of the skin following the regular removal of appliances, which can have a detrimental impact on skin barrier function. Unless effectively managed, complications can become costly to treat over time, as well as having a negative impact on psychological well-being and quality of life. Novel skin adhesives intended for ostomy care should possess the capability to maintain and promote the healthy condition of the skin it is in contact with, whilst balancing comfort and security against leakage during the desired wear time.

[0006] Traditional skin compatible adhesive formulations for use in ostomy care or wound management are typically composed of mixtures of polyisobutylene and / or polyisoprene rubbers, and tackifiers, in addition to various combinations of additives, such as cohesive strengthening agents, plasticizers, rheology modifiers, and absorbents. Such formulations are designed to manage moisture, whether from sweat, exudate, or other fluid, primarily through mechanisms of absorption and capture. However, the uptake of fluids by such adhesives can result in degradation, potentially compromising secure adhesion. Also, this increases the risk of exposing the underlying skin to undesired effluent which 2Ref: H16904WO / MZCwould detrimentally affect skin health by promoting further complications. Moreover, such compositions tend to display aggressive adhesion, resulting in mechanical stripping of the skin on removal. Repeated skin stripping can severely compromise skin barrier function by increasing trans epidermal water loss, promoting redness and irritation, and increasing the risk of infection. Furthermore, such traditional adhesive formulations can fall short in terms of providing adequate moisture and gas transmission (e.g., oxygen), which are important features for maintaining skin health. Adhesives that can allow for elevated levels of moisture and gas transmission can be considered breathable. A breathable adhesive enables skin to properly regulate temperature and humidity via vapor exchange, which helps to maintain the skin surface microenvironment.

[0007] Alternatively, adhesive formulations for use in ostomy care or wound management can be composed of polysiloxane-based adhesives. Such formulations are designed to manage moisture, whether from sweat, exudate, or other fluid, primarily through mechanisms of moisture vapor transmission, as well as absorption and capture.

[0008] One known approach involves the use of a composition prepared with a silicone adhesive raw material that has a high solvent content. A disadvantage with this approach is that preparing such formulations requires additional measures to safely manage any hazardous quantities of solvent vapor that would evolve during processing of the composition.

[0009] Another known approach involves the use of gel-based adhesive formulations comprising a two-part silicone system. These systems were developed to overcome the performance limitations of traditional skin compatible formulations, including degradation on absorption of moisture, traumatic removal, and inadequate moisture vapor transmission. Whilst such adhesives are gentle on skin and atraumatic to remove, they are poorly absorbative compared to traditional adhesive formulations. In such gel-based adhesive formulations, a liquid hydrophilic network promoter is incorporated. The addition of such additives can3Ref: H16904WO / MZCreduce tack adhesion, requiring the addition of tackifiers to modify adhesion performance parameters. Inability to effectively manage excess moisture can negatively impact adhesive performance during practical use, leading to issues such as adhesive failure and leakage. Another disadvantage of such gel-based adhesive formulations is that they are based on silicone two-part adhesives which have inherently low shear resistance, which limits their potential to secure secondary medical devices.

[0010] One such example of a marketed silicone adhesive technology is Genii™ manufactured by Trio Healthcare Limited. This technology is formulated around a 2-part silicone system with additives to enhance breathability and absorption. Being gel-based, the adhesive is gentle to skin on removal. However, as silicone is inherently hydrophobic, the absorbative ability of adhesives such as Genii™ is less than that of traditional adhesive formulations based on polyisobutylene (PIB). Inability to manage moisture effectively away from the source, can lead to skin maceration and adhesive de-bonding. Furthermore, the addition of additives to these systems can compromise adhesion performance parameters, such as tack and longevity of attachment to skin. Lastly, such technologies also come with higher raw materials costs, with 2-part silicone systems typically costing in the region of approximately 1.5 to 2.0 times more than that of polyisobutylene (PIB).

[0011] In summary:

[0012] (a) current adhesives can cause mechanical damage to the underlying skin on removal. This is typically overcome by using additional accessory products, such as skin barriers or adhesive removers that assist in protecting the skin and assisting removal, respectively. A solution to this is to use gentler gel-based adhesives, such as those comprising a 2-part silicone system, however, these offer insufficient shear resistance to support secondary medical devices, are generally poor at absorbing moisture, and can be expensive to manufacture.4Ref: H16904WO / MZC

[0013] (b) Current adhesives offer limited moisture vapor and gas transmission and are thus associated with being poorly breathable. Breathability is a key performance parameter that enables the effective regulation of the temperature and humidity balance required to maintain skin health. Sufficient levels of breathability may be achieved by providing conventional adhesives in thinner layers; however, this is compromising to overall fluid handling capacity and shear resistance.

[0014] (c) Gel-based adhesives, such as those comprising a 2-part silicone system, lack the capacity to absorb and manage moisture effectively away from the source, potentially causing maceration and adhesive de-bonding. This may be overcome by increasing the absorbent filler content of these adhesives or introducing hydrophilic network promotors; however, the addition of additives to these systems can comprise adhesion performance parameters, such as tack and longevity of attachment to skin.

[0015] It is desirable to have an adhesive composition with the ability to provide secure adhesion during wear, absorb moisture, allow skin to breathe and be adaptive to moisture levels, and be gentle to remove as to avoid skin stripping that compromises skin barrier function.

[0016] The present invention seeks to achieve this goal.

[0017] SUMMARY OF INVENTION

[0018] In general, this disclosure describes skin compatible silicone-based adhesive compositions for attaching medical devices to mammalian skin that are comprised of composite mixtures of silicone pressure sensitive adhesive and additives intended to provide a balance of properties beneficial to end-user experience and skin health, including security, atraumatic adhesion, moisture capture, and moisture and gas transmission.

[0019] There is provided an adhesive composition comprising a polysiloxane adhesive. The adhesive composition may comprise a reinforcing 5Ref: H16904WO / MZCcomponent. The adhesive composition may comprise a plasticizing component. The adhesive composition may comprise an absorbing component.

[0020] In one aspect, the adhesive composition may comprise, consist essentially of, or consist of a polysiloxane adhesive, a reinforcing component, a plasticizing component and an absorbing component.

[0021] In another aspect, the adhesive composition may comprise, consist essentially of, or consist of a polysiloxane adhesive, a reinforcing component and an absorbing component, wherein the reinforcing component constitutes less than about 5.0% by weight of the total weight of the adhesive composition.

[0022] In another aspect, the adhesive composition may comprise, consist essentially of, or consist of a polysiloxane adhesive, a reinforcing component and an absorbing component, wherein the polysiloxane adhesive constitutes less than about 40.0% by weight of the total weight of the adhesive composition.

[0023] In another aspect, the adhesive composition may comprise, consist essentially of, or consist of a polysiloxane adhesive, a reinforcing component and an absorbing component, wherein the polysiloxane adhesive has a solids content of about 100%.

[0024] In another aspect, the adhesive composition may comprise, consist essentially of, or consist of a polysiloxane adhesive, a reinforcing component and an absorbing component, wherein the adhesive composition comprises a complex shear modulus for 0.001 % strain at 25°C in the range of about 1.0x105Pa to about 1.0x107Pa.

[0025] The polysiloxane adhesive may be a one-part adhesive. Advantageously, the utilization of a one-part polysiloxane adhesive can result in a more breathable adhesive composition in terms of moisture and gas - particularly oxygen - transmission.

[0026] The polysiloxane adhesive may be at least partially crosslinked.6Ref: H16904WO / MZC

[0027] The polysiloxane adhesive may have a solids content of about 100%. Accordingly, the polysiloxane adhesive may be supplied in a solvent-free form.

[0028] The polysiloxane adhesive may constitute about 30.0% to about 45.0% by weight of the total weight of the adhesive composition. The polysiloxane adhesive may constitute about 32.5% to about 42.5% by weight of the total weight of the adhesive composition. The polysiloxane adhesive may constitute about 35.0% to about 40.0% by weight of the total weight of the adhesive composition. The polysiloxane adhesive may constitute less than about 40.0% by weight of the total weight of the adhesive composition. The polysiloxane adhesive may constitute from about 30%, about 31%, about 32%, about 33%, about 34%, about 35%, about 36%, about 37%, about 38% or about 39% to about 31%, about 32%, about 33%, about 34%, about 35%, about 36%, about 37%, about 38%, about 39% or about 40% by weight of the total weight of the adhesive composition.

[0029] The reinforcing component may be selected from the group consisting of fumed silica, fumed alumina, colloidal silica, nano-clays, silicates, silane treated organic polymers, polymeric metal oxides, non-polymeric metal oxides, and any combination thereof.

[0030] The reinforcing component may be a fumed silica.

[0031] The reinforcing component, e.g., the fumed silica, may comprise: a SiO2 content of about 90% to about 99%, such as about 95% to about 99%, e.g., about 99%.

[0032] The reinforcing component, e.g., the fumed silica, may comprise a specific surface area (BET) in the range of about 50.0 m2 / g to about 600.0 m2 / g.

[0033] The reinforcing component, e.g., the fumed silica, may comprise a pH value in the range of about 3.5 to about 5.5.

[0034] The reinforcing component, e.g., the fumed silica, may comprise a density in the range of about 150.0 kg / m3to about 200.0 kg / m3.7Ref: H16904WO / MZC

[0035] The reinforcing component may constitute about 1.0% to about 5.0% by weight of the total weight of the adhesive composition. The reinforcing component may constitute from about 1.0%, about 1.5%, about 2.0%, about 2.5%, about 3.0%, about 3.5%, about 4.0% or about 4.5% to about 1.5%, about 2.0%, about 2.5%, about 3.0%, about 3.5%, about 4.0%, about 4.5% or about 5.0% by weight of the total weight of the adhesive composition.

[0036] The adhesive composition may comprise a plasticizing component. The plasticizing component may constitute about 1.0% to about 6.5% by weight of the total weight of the adhesive composition. The plasticizing component may constitute from about 1.0%, about 1.5%, about 2.0%, about 2.5%, about 3.0%, about 3.5%, about 4.0%, about 4.5%, about 5.0%, about 5.5% or about 6.0% to about 1.5%, about 2.0%, about 2.5%, about 3.0%, about 3.5%, about 4.0%, about 4.5%, about 5.0%, about 5.5%, about 6.0% or about 6.5% by weight of the total weight of the adhesive composition.

[0037] The plasticizing component may be selected from the group consisting of silicone fluids, phthalates, phosphate esters, polyisobutylenes, fatty acid esters, polyalkylbenzenes, and any combination thereof.

[0038] The plasticizing component may be a hydroxyl terminated silicone fluid, such as hydroxyl terminated polydimethylsiloxane.

[0039] The plasticizing component, e.g., the hydroxyl terminated silicone fluid, may have a density in the range of from about 0.5 g / mL to about 5 g / mL, such as from about 0.5 g / mL to about 2.5 g / mL, such as from about 0.5 g / mL to about 1.5 g / mL, e.g., 0.98 g / mL.

[0040] The plasticizing component, e.g., the hydroxyl terminated silicone fluid, may have a viscosity <45 cSt.

[0041] The plasticizing component, e.g., the hydroxyl terminated silicone fluid, may have a hydroxyl content of >3.8%.8Ref: H16904WO / MZC

[0042] The absorbing component may be selected from the group consisting of agar-agar, gelatine, locust bean gum, guar gum, pectin, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, hydroxypropyl cellulose, alginate, carrageenan, xanthan gum, tragacanth gum, konjac gum, starch, chitosan, sodium polyacrylate, potassium polyacrylate, and any combination thereof.

[0043] The absorbing component may comprise, consist of or consist essentially of a combination of (i) carboxymethyl cellulose and (ii) gelatine.

[0044] The carboxymethyl cellulose may comprise a D80 particle size distribution of from approximately 50 microns to approximately 250 microns, such as from approximately 50 microns to approximately 200 microns, such as from approximately 50 microns to approximately 150 microns, such as from approximately 50 microns to approximately 1000 microns, e.g., approximately 75 microns.

[0045] The carboxymethyl cellulose may comprise a sodium content in the range of about 6.0% to about 9.0%.

[0046] The carboxymethyl cellulose may comprise a viscosity for a 1.0% solution at 25 °C in the range of about 10.0 mPa.s to about 5000.0 mPa.s.

[0047] The gelatine may comprise a particle size in the range of from about 8.0 mesh to about 200.0 mesh.

[0048] The gelatine may comprise a Bloom strength in the range of about 30.0 g Bloom to about 300.0 g Bloom.

[0049] The gelatine may comprise a pH value in the range of about 4.5 to about 6.0.

[0050] The absorbing component may constitute about 45.0% to about 75.0% by weight of the total weight of the adhesive composition. The absorbing component may constitute from about 45.0%, about 50.0%, about 55.0%, about 9Ref: H16904WO / MZC60.0 %, about 65.0% or about 70.0% to about 50.0%, about 55.0%, about 60.0%, about 65.0%, about 70.0% or about 75.0% by weight of the total weight of the adhesive composition.

[0051] In one example, the adhesive composition may comprise, consist essentially of, or consist of a polysiloxane adhesive, a reinforcing component, a plasticizing component and an absorbing component, wherein the adhesive composition comprises about 30% to about 45% of the polysiloxane adhesive, about 1.0% to about 5.0% of the reinforcing component, about 1.0% to about 6.5% of the plasticizing component and about 45.0% to about 75.0% of the absorbing component, wherein the percentages are based on the total weight of the adhesive composition.

[0052] In one example, the adhesive composition may comprise, consist essentially of, or consist of a polysiloxane adhesive, a reinforcing component, a plasticizing component and an absorbing component, wherein the adhesive composition comprises about 30% to about 39% of the polysiloxane adhesive, about 2.0% to about 5.0% of the reinforcing component, about 1.0% to about 5.0% of the plasticizing component and about 45.0% to about 70.0% of the absorbing component, wherein the percentages are based on the total weight of the adhesive composition.

[0053] In one example, the adhesive composition may comprise, consist essentially of, or consist of a polysiloxane adhesive, a reinforcing component, a plasticizing component and an absorbing component, wherein the adhesive composition comprises about 35% to about 39% of the polysiloxane adhesive, about 2.0% to about 4.0% of the reinforcing component, about 1.0% to about 4.0% of the plasticizing component and about 50.0% to about 65.0% of the absorbing component, wherein the percentages are based on the total weight of the adhesive composition.

[0054] In one example, the adhesive composition may comprise, consist essentially of, or consist of a polysiloxane adhesive, a reinforcing component, a10Ref: H16904WO / MZCplasticizing component and an absorbing component, wherein the adhesive composition comprises about 35% to about 38% of the polysiloxane adhesive, about 2.0% to about 3.0% of the reinforcing component, about 1.0% to about 2.5% of the plasticizing component and about 55.0% to about 60.0% of the absorbing component, wherein the percentages are based on the total weight of the adhesive composition.

[0055] The adhesive composition may comprise a complex shear modulus for 0.001% strain at 25°C in the range of about 1.0x105Pa to about 1.0x107Pa, such as about 1.0x105Pa to about 1.0x106Pa.

[0056] In a further aspect there is provided a base plate for an ostomy device, the base plate comprising a layer of the adhesive composition having a first surface and a second surface, wherein a backing layer is laminated to the first surface.

[0057] The backing layer may be moisture permeable. The backing layer may have a thickness of about 0.8 mm to about 1.2 mm, such as about 0.9 mm.

[0058] The base plate may have an oxygen gas transmission rate therethrough from about 10,000 cm3 / m2 / 24h to about 30,000 cm3 / m2 / 24h when performed in accordance with ASTM F1927-20 at a temperature of 37 °C and a relative humidity of 19 %.

[0059] For instance, the oxygen gas transmission rate may be from about 10,000 cm3 / m2 / 24h, 11,000 cm3 / m2 / 24h, 12,000 cm3 / m2 / 24h, 13,000 cm3 / m2 / 24h, 14,000 cm3 / m2 / 24h, 15,000 cm3 / m2 / 24h, 16,000 cm3 / m2 / 24h, 17,000 cm3 / m2 / 24h, 18,000 cm3 / m2 / 24h, 19,000 cm3 / m2 / 24h, 20,000 cm3 / m2 / 24h, 21,000 cm3 / m2 / 24h, 22,000 cm3 / m2 / 24h, 23,000 cm3 / m2 / 24h, 24,000 cm3 / m2 / 24h, 25,000 cm3 / m2 / 24h, 26,000 cm3 / m2 / 24h, 27,000 cm3 / m2 / 24h, 28,000 cm3 / m2 / 24h, 29,000 cm3 / m2 / 24h to 11,000 cm3 / m2 / 24h, 12,000 cm3 / m2 / 24h, 13,000 cm3 / m2 / 24h, 14,000 cm3 / m2 / 24h, 15,000 cm3 / m2 / 24h, 16,000 cm3 / m2 / 24h, 17,000 cm3 / m2 / 24h, 18,000 cm3 / m2 / 24h, 19,000 cm3 / m2 / 24h, 20,000 cm3 / m2 / 24h, 21,000 cm3 / m2 / 24h, 22,00011Ref: H16904WO / MZCcm3 / m2 / 24h, 23,000 cm3 / m2 / 24h, 24,000 cm3 / m2 / 24h, 25,000 cm3 / m2 / 24h, 26,000 cm3 / m2 / 24h, 27,000 cm3 / m2 / 24h, 28,000 cm3 / m2 / 24h, 29,000 cm3 / m2 / 24h, 30,000 cm3 / m2 / 24h when performed in accordance with ASTM F1927-20 at a temperature of 37 °C and a relative humidity of 19 %.

[0060] The base plate may further comprising a release liner, wherein the release liner is laminated to the second surface of the layer of adhesive composition.

[0061] In a further aspect there is provided an ostomy device comprising the base plate and a pouch for collecting stomal discharge, wherein the base plate and the pouch are connected or connectable to one another.

[0062] As used herein the term silicone (or polysiloxane) can be described as polymer with any number of repeating siloxane units. The arrangement of siloxane units may be linear, cyclic, branched, or combinations thereof. Siloxane can be represented as -(O-SiR2)n- where R can be any organic or inorganic functional group and n represents the number of repeating monomer units.

[0063] As used herein the term pressure sensitive adhesive composition can be described as an adhesive that can form a bond with a substrate on application of a range of forces via physical contact. Typically, medical devices are secured to mammalian skin by pressing with a digit or hand. The maximum force that can be applied by an individual human digit can range from between 30 N to 60 N, whereas the maximum force that can be applied by a human hand can range from between 300 N to 350 N.12Ref: H16904WO / MZC

[0064] As used herein the term silicone-based pressure sensitive adhesive composition refers to a homogenous mixture of silicone polymer blended with silicone compatible tackifier component to provide properties of tack, peel, and shear.

[0065] The disclosure relates to adhesive compositions that can be utilized as part of a ‘wafer’ or ‘baseplate’ for securing colostomy, ileostomy, and / or urostomy output ‘collection devices’ to peristomal skin. Such ‘collection devices’ may take the form of a closed or drainable bag, depending on the output collected.

[0066] Other feasible uses of the disclosed adhesive compositions may include the treatment of wounds, pressure ulcers, other types of ulcers, and superficial burns.

[0067] It will be appreciated that many features of an aspect of the present technology will also be applicable to many, or all, other aspects of the technology.

[0068] BRIEF DESCRIPTION OF THE DRAWINGS

[0069] In order that the present disclosure may be more readily understood, preferable embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0070] Figure 1 shows various diagrammatic representations of the chemical structure of a polysiloxane, where R, Ri, R2, R3 and R4 each represent an organic or inorganic substituent including H, and wherein n and ri each represent the number of repeating monomer units. The two substituents on the silicon atom may be the same (A) or different (B). The substituents on each silicon atoms can vary (C). The substituents can be arranged as a block co-polymer (D).

[0071] Figure 2 is a diagrammatic representation of the chemical structure of a hydroxyl terminated polysiloxane.

[0072] Figure 3 shows viscoelastic window profiles for adhesive formulations constructed utilizing rheological frequency sweep data collected 13Ref: H16904WO / MZCbetween 0.06 and 125 rad / s at a strain of 0.001 % and temperature of 25.0 °C. The viscoelastic regions are defined as follows: removable PSA (low modulus and low dissipation), general purpose PSA (medium modulus and medium dissipation), and high shear PSA (high modulus and high dissipation).

[0073] Figure 4 shows plots of water vapor moisture handling properties of adhesive formulations conditioned at 37.0 °C and 19.0% relative humidity for 24 h. The data were acquired according to the ASTM E96 standard. Samples were prepared from extruded adhesive with a thickness of ca. 0.9 mm topped with medical backing MED5712P by Avery Dennison Corporation. TRIOHEALTHCARE™ GENII™ samples were prepared from ostomy wafers without further modification. Bar heights are the average of n = 3 samples with the plus error bar representative of standard deviation.

[0074] Figure 5 shows plots of saline (0.9%) moisture handling properties of adhesive formulations conditioned at 37.0 °C and 19.0% relative humidity for 24 h. The data were acquired according to the BS EN 13726-1. Samples were prepared from extruded adhesive with a thickness of ca. 0.9 mm topped with medical backing MED5712P by Avery Dennison Corporation. TRIOHEALTHCARE™ GENII™ samples were prepared from ostomy wafers without further modification. Bar heights are the average of n = 3 samples with the plus error bar representative of standard deviation.

[0075] Figure 6 is a perspective view of a Paddington cup utilized for determining water vapor moisture handling properties of adhesive formulations.

[0076] Figure 7 is a perspective view of a Paddington cup utilized for determining saline (0.9%) moisture handling properties of adhesive formulations.

[0077] DETAILED DESCRIPTION OF THE INVENTION

[0078] Polysiloxane adhesives14Ref: H16904WO / MZC

[0079] A silicone (otherwise termed polysiloxane) can be described as polymer with any number of repeating siloxane units, n (Figure 1). The arrangement of siloxane units may be linear, cyclic, branched, or any combination thereof. Siloxane can be represented as -(O-SiR2)n- where R can be any organic or inorganic functional group and n represents the number of repeating monomer units. Furthermore, the identity of the functional groups on an individual silicon atom does not have to be the same, i.e., -(O-SiRiR2)n-, where Ri and R2 have different chemical compositions. Furthermore, the identity of the functional groups on all silicon atoms does not have to be the same, i.e., -(O-SiRiR2-O-SiR3R4)n-, where R1, R2, R3 and R4 can have different chemical compositions. Finally, the polysiloxane may have substituents arranged in block, i.e., a block co-polymer -(O-SiRiR2)n-(O-SiR3R4)n -, where n and n’ can be the same or different.

[0080] Hydroxyl terminated polysiloxanes can be represented by the chemical structure shown in Figure 2, where R can be any organic or inorganic functional group. R can be any organic or inorganic group and is not limited to being one group at any given position in the chemical structure. Where R is a methyl group the polysiloxane is hydroxyl terminated polydimethylsiloxane.

[0081] In embodiments, the polysiloxane adhesive is a one-part, pre-cured (crosslinked) adhesive that is solvent free. This form of adhesive may technically be referred to as a hot melt adhesive. In embodiments, the polysiloxane adhesive is a polysiloxane pressure sensitive adhesive or a polyorganosiloxane based pressure sensitive adhesive. In embodiments, the polysiloxane adhesive is a polysiloxane pressure sensitive available commercially under the trade name Liveo™ from DuPont de Nemours, Inc. Examples of medical grade pressure sensitive adhesives under the trade name Liveo™ include MG-2401 , MG-2402, MG-2502, MG-2410, and the like. These are examples of one-part polysiloxane adhesives that are crosslinked by the supplier which come either dispersed in a commercially available solvent, such as ethyl acetate or hexamethyldisiloxane, or in a solvent free form (100% solids). In embodiments, the polysiloxane is MG-2410, which is an example of a solvent free grade (100% solids). Liveo™ MG-2410 is15Ref: H16904WO / MZCproduced through a condensation reaction of a silanol end blocked polydimethylsiloxane (PDMS) with a silicate resin, plasticized with polydimethylsiloxane fluid. It is contemplated that other grades provided as examples could be used in combination to provide an adhesive with the properties desired.

[0082] Polysiloxane adhesives are also commercially available under the trade name NuSil® from Nusil Technology LLC. Examples of suitable grades of polysiloxane adhesive under the trade name NuSil® include PSA-1170, PSA-1180, PSA-1270, and the like.

[0083] Polysiloxane adhesives are also commercially available under the trade name XJY Silicones® from Jiangxi New Jiayi New Materials Co Ltd. Examples of suitable grades of polysiloxane adhesive under the trade name XJY Silicones® include XJY-301 -1 , XJY-301 -2, XJY-301 -3, XJY-301 -4, and the like.

[0084] According to the present disclosure, polysiloxane adhesives may contain one or more polar or non-polar chemical moieties on the polydimethylsiloxane backbone. Non-limiting examples of such groups include acid, amido, amino, sulfonyl, carboxyl, phosphate, phosphonate, alcohol, methyl, and the like. Such groups may be present in any number of non-limiting combinations on the polydimethylsiloxane backbone. An example of a segment of the polydimethylsiloxane backbone chemical structure is shown in Figure 1 whereby functional moieties are represented by R.

[0085] When combined with additives, polysiloxane adhesives may provide improved adhesive performance properties, such as improved tack and improved peel strength. To achieve a balance of all property requirements necessary for practical performance, the amounts of various additives combined with the polysiloxane adhesive may be adjusted. Typically, if a higher tack and stronger peel adhesion strength is required, the amount of polysiloxane adhesive included in the composition can be increased.16Ref: H16904WO / MZC

[0086] Reinforcing component

[0087] In embodiments, the reinforcing component of the present disclosure comprises one or more typically solid particulate powders. Non-limiting examples of reinforcing components include fumed silica, fumed alumina, colloidal silica, nano-clays, silicates, silane treated organic polymers, polymeric metal oxides, non-polymeric metal oxides, and the like. The reinforcing component may be inherently hydrophilic or hydrophobic. Additionally, the reinforcing component may be modified in such a way as to engender hydrophilic or hydrophobic properties as desired. In embodiments, the reinforcing component is a fumed silica. In embodiments, the reinforcing component is a fumed silica available commercially under the trade name Aerosil® from Evonik Industries AG. Examples of suitable grades of fumed silica under the trade name Aerosil® include 200 Pharma, 300 Pharma, R812, R812S, R7200, R8200, R9200, and the like. In embodiments, the grade is 200 Pharma, an example of an inherently hydrophilic grade. It is contemplated that other grades provided as examples could be used in combination to provide an adhesive with the properties desired.

[0088] Reinforcing components consisting of fumed silica are also commercially available under the trade name CAB-O-SIL® from CABOT. Examples of suitable grades of fumed silica under the trade name CAB-O-SIL® include H5, H300, LM150, M5, CT1221, and the like.

[0089] Reinforcing components consisting of fumed silica are also commercially available under the trade name HDK® from Wacker Chemie AG. Examples of suitable grades of fumed silica under the trade name HDK® include N20Plus, T30Plus, H20, H30, and the like.

[0090] When combined with other components of the adhesive formulation the reinforcing component can provide improved performance properties, such as improved cohesive strength and / or improved rheological behavior. Furthermore, use of reinforcing components that are hydrophilic can improve moisture handling properties, such as static absorption and moisture vapor transmission rate, through17Ref: H16904WO / MZCthe provision of a hydrophilic network at certain inclusion levels. To achieve a balance of all property requirements necessary for practical performance, the amounts of various additives combined with the reinforcing component may be adjusted. Typically, if a stiffer and more cohesive adhesive is required, the amount of reinforcing component included in the composition can be increased.

[0091] Plasticizing component

[0092] In embodiments, the plasticizing component of the present disclosure comprises one or more synthetic fluids, semi-solids, or emollients. Nonlimiting examples of plasticizing components include silicone fluids, phthalates, phosphate esters, polyisobutylenes, fatty acid esters, polyalkylbenzenes, and the like. The plasticizing component may be inherently reactive or non-reactive. In embodiments, the plasticizing component is a silicone fluid. In embodiments, the plasticizing component is a silicone fluid available commercially under the trade name SISI B® from Nanjing SiSiB Silicones Co Ltd. Examples of suitable grades of silicone fluid under the trade name SiSiB® include MF2010-5, MF2010-10, MF2010-20, MF2010-50, OF0035, OF0042, and the like. In embodiments, the grade is OF0035, an example of a low molecular weight reactive silicone fluid in the form of hydroxyl terminated linear polydimethylsiloxane. It is contemplated that other grades provided as examples could be used in combination to provide an adhesive with the properties desired. An example of the structure of hydroxyl terminated linear polydimethylsiloxane chemical structure is shown in Figure 2, where each R is a methyl group and n is any integer.

[0093] When combined with other components of the adhesive formulation the plasticizing component may provide improved performance properties, such as improved ductility and / or improved rheological behavior. Furthermore, use of plasticizing components consisting of low molecular weight hydroxyl silicone fluid can extend the storage life of formulations susceptible to time-dependent physicalchemical changes. Time-dependent physical-chemical changes may include creep hardening, caused by the formation of hydrogen bonds between fumed silica18Ref: H16904WO / MZCreinforcing component and polyorganosiloxane pressure sensitive adhesive. This phenomenon alters physical properties, which has a detrimental impact on adhesive performance. Use of a plasticizing component comprising a low molecular weight hydroxyl silicone fluid can counter the formation of undesired hydrogen bonding, mitigating against time-dependent physical-chemical changes. To achieve a balance of all property requirements necessary for practical performance, the amounts of various additives combined with the plasticizing component may be adjusted. Typically, if a softer and more ductile adhesive is required, the amount of plasticizing component included in the composition can be increased.

[0094] Absorbing component

[0095] In embodiments, the absorbing component of the present disclosure comprises one or more typically hydrocolloid, peptide, or superabsorbent polymer powders. Non-limiting examples of absorbing components include agar-agar, gelatine, locust bean gum, guar gum, pectin, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, hydroxypropyl cellulose, alginate, carrageenan, xanthan gum, tragacanth gum, konjac gum, starch, chitosan, sodium polyacrylate, potassium polyacrylate, and the like. The absorbing component may be inherently neutral, polyanionic, or cationic. In embodiments, the absorbing component is a combination of carboxymethyl cellulose and gelatine. In embodiments, the absorbing component comprises a carboxymethyl cellulose available commercially under the trade name Cekol®from Nouryon BV. Examples of suitable grades of carboxymethyl cellulose under the trade name Cekol® include 2000P, 10000, 20000, 30000, 30000P, and the like. In embodiments, the grade is 30000P. It is contemplated that other grades provided as examples could be used in combination to provide an adhesive with the properties desired. In embodiments, the absorbing component comprises a gelatine available commercially under the trade name HydroLux® from Arthur Branwell & Co Ltd. Examples of suitable grades of gelatine under the trade name HydroLux® include 405-12 BP-USP, 405-12BGD, and the like. In embodiments, the grade is 405-12BGD. It is contemplated that19Ref: H16904WO / MZCother grades provided as examples could be used in combination to provide an adhesive with the properties desired.

[0096] Absorbing components consisting of carboxymethyl cellulose are also commercially available under the trade name Aquasorb™ from Ashland Inc. Examples of suitable grades of carboxymethyl cellulose under the trade name Aquasorb™ include A200PH, A380, A500, A800, and the like.

[0097] When combined with other components of the adhesive formulation, the absorbing component can provide improved performance properties, such as improved moisture capture and / or improved rheological behavior. Furthermore, the absorbing component can influence the gel strength of formulations. A suitable gel strength can mitigate the degradation of the adhesive following absorption of moisture, which would otherwise compromise adherence to and health of underlying skin. To achieve a balance of all property requirements necessary for practical performance, the amounts of various additives combined with the absorbing component may be adjusted. Typically, if a more absorbent adhesive is required, the amount of absorbing component included in the composition can be increased.

[0098] EXAMPLES

[0099] Table 1 details example adhesive compositions according to the present disclosure. Comments on the suitability of the prospective formulations are provided. Possible compositions of the present invention are not limited to those detailed in Table 1.Table 1. Compositional details of example formulations with comments.20Ref: H16904WO / MZC21Ref: H16904WO / MZC22Ref: H16904WO / MZC23Ref: H16904WO / MZC

[0100] Table 2 details the steps involved in the preparation of examples according to the present disclosure. Example formulations of a 50 g basis were prepared using a Thermo Scientific HAAKE™ PolyLab™ QC system equipped with Banbury rotors. The temperature was set at 80 °C and the mixing speed was set to 20 rpm. Methods of preparation of the present invention are not limited to the steps outlined in Table 2.Table 2. Mixing steps for the preparation of example adhesives.24Ref: H16904WO / MZC

[0101] Following mixing sample formulations were extruded using a Thermo Scientific HAAKE™ PolyLab™ OS RheoDrive 7 system equipped with a heated sheet extruder. The temperature was set at 80°C, the extrusion screw speed was set to 20 rpm, and the extrusion thickness was set to 0.9mm. If required, 50g basis batches were combined to provide sufficient material for the extruder. Extruded sheets of adhesive were collected between two sheets of protective polyethylene film. For the preparation of samples for rheological characterization, discs were cut from this construction. For the preparation of samples for adhesion and moisture handling characterization, polyethylene was removed from one side of the adhesive and replaced with a breathable medical backing. To ensure even application of the backing, a FINAT roller was used. The selected backing was MED5712P supplied by Avery Dennison Corporation, which offers a moisture vapor transmission rate of 2300 g / m2 / day (Avery Dennison TDS-16: Moisture Vapor Transmission Rate). This backing offers high moisture vapor transmission and was selected to enable moisture to freely transfer through the adhesive to external environment. The remaining polyethylene layer served as the adhesive release liner. As required, discs and strips of this construction were utilized for adhesion and moisture handling characterization.25Ref: H16904WO / MZC

[0102] Rheological frequency sweep data were collected between 0.06 and 125 rad / s at a strain of 0.001 % and temperature of 25.0 °C using a Kinexus® rheometer supplied by Netzsch-Geratebau GmbH. Values of G’ and G” values at 0.1 and 100 rad / s, respectively, were extracted from datasets to construct viscoelastic window profiles, as shown in Figure 3.

[0103] Figure 3 is a comparison of the viscoelastic window profiles for examples 4, 6, 7 and 10 against the GENII™ (an adhesive composition based on a two-part polysiloxane) and CONFIDENCE BE® by SALTS HEALTHCARE (an adhesive composition based on a polyisobutylene system). Examples 4, 6, 7 and 10 and CONFIDENCE BE® fall within the high shear pressure sensitive adhesive (PSA) quadrant and the GENII™ falls within the general purpose PSA quadrant. These data indicate that examples 4, 6, 7 and 10 have a higher shear resistance than GENII™. These data also indicate that examples 4, 6, 7 and 10 have a comparable shear resistance to CONFIDENCE BE®. An adhesive falling within the high shear PSA quadrant generally indicates that the adhesive offers a good balance of adhesion, peel, and shear resistance. Furthermore, a wider viscoelastic coordinate spread within the high shear PSA quadrant may indicate that the adhesive achieves suitable tack (lower frequency response) and peel performance (higher frequency response).

[0104] Equipment for water vapour moisture handling analysis included a Paddington cup 1, as shown in Figure 6. The Paddington cup 1 has a 3.5 cm diameter sample opening 2 and a mounting ring 3. The Paddington cup 1 has a sealed top (i.e., no screw cap). Other equipment included distilled water, an environmental control chamber set at 37.0 °C and 19.0% relative humidity, and analytical scales. The cup assemblies, together with adhesive discs (42.0 mm diameter) backed with MED5217P, were weighed to three decimal places (W1). With the sample opening 2 facing up, the units filled with 10mL distilled water, before adhesive discs (42.0 mm) backed with MED5217P backing were secured to the Paddington cups 1 over the sample opening and secured in place with the mounting ring 3. The cup assemblies were orientated such that distilled water was26Ref: H16904WO / MZCnot in contact with the adhesive samples. The cup assemblies were then weighed to three decimal places (W2). The cup assemblies were then stored in an environmental control chamber set at 37.0 °C and 19.0% relative humidity for 24 h. The cup assemblies were then removed from the environmental control chamber and maintained at ambient conditions for 30 min. The cup assemblies were then weighed to three decimal places (W3). The mounting ring 3 was then loosened, adhesive samples peeled back, and the units drained of remaining distilled water. The cup assemblies were then inverted and placed on tissue to allow any remaining distilled water to drain for a further 20 min. The cup assemblies were then weighed to three decimal places (W4). All measurements were recorded in grams (g).

[0105] Equipment for saline (0.9%) moisture handing analysis included a Paddington cup 1', as shown in Figure 7. The Paddington cup 1' has a 3.5 cm diameter sample opening 2' and a mounting ring 3'. The Paddington cup 1' has a screw-cap 4'. Other equipment included a saline solution prepared to a concentration of 0.9% (NaCI in distilled water), an environmental control chamber set at 37.0 °C and 19.0% relative humidity, and analytical scales. With the sample opening 2' facing up, adhesive discs (42.0 mm) backed with MED5217P backing were secured to the Paddington cups 1' over the sample opening 2' and secured in place with the mounting ring 3'. The cup assemblies were then weighed to three decimal places (W1). The cup assemblies were then inverted, the screw caps removed, and the units filled with 20.0 mL saline (0.9%), before replacing the screw caps to seal the units. The cup assemblies were orientated such that saline was in constant contact with the adhesive sample. The cup assemblies were then weighed to three decimal places (W2). The cup assemblies were then stored in an environmental control chamber set at 37.0 °C and 19.0% relative humidity for 24 h. The cup assemblies were then removed from the environmental control chamber and maintained at ambient conditions for 30 min. The cup assemblies were then weighed to three decimal places (W3). The screw caps were then removed, and the units drained of remaining saline. The cup assemblies were then inverted and placed on tissue to allow any remaining saline to drain for a further 27Ref: H16904WO / MZC20 min. The cup assemblies were then weighed to three decimal places (W4). All measurements were recorded in grams (g).

[0106] Adhesive sample moisture vapor transmission rate (MVTR) was calculated in units of g / m2 / 24 h using the following formula:

[0107] MVTR = (W2-W3) x 1000

[0108] Static absorption (SA) was calculated in units of g / m2 / 24 h using the following formula:

[0109] SA = (W4-W1) x 1000

[0110] Overall fluid-handling capacity consists of a combination of both static absorption and water vapor transmission. Fluid-handling capacity was calculated in units of g / m2 / 24 h using the following formula:

[0111] FHC = SA + MVTR

[0112] The moisture handling properties of examples 4, 6, 7 , 10, GENII™ and CONFIDENCE BE® acquired and processed according to the ASTM E96 standard are shown in Table 3 and Figure 4. This test is indicative of the water vapor moisture handling properties of adhesive compositions not in direct contact with fluid. The experimental set-up may be considered a proxy for scenarios requiring a low volume of bodily fluid to be managed, including but not limited to sweat, wound exudate and excrement. Typical scenarios may include but are not limited to coverage of a low exudating wound, performance of low intensity exercise, and general daily wear.

[0113] Table 3. Moisture handing properties (ASTM E96 standard)28Ref: H16904WO / MZC

[0114] These data show that examples 4, 6, 7 and 10 can achieve improved moisture vapour transmission rates when compared to GENII™ and CONFIDENCE BE®. For instance, example 10 achieves a 133% and a 123% improvement in moisture vapour transmission rate compared to GENII™ and CONFIDENCE BE®, respectively. These data also show that examples 4, 6, 7 and 10 can achieve improved fluid handling capacities when compared to GENII™ and CONFIDENCE BE®. For instance, example 10 achieves a 108% improvement in fluid handling capacity over GENII™ and about a 19% increase in fluid handling capacity over CONFIDENCE BE®. This indicates that examples 4, 6, 7 and 10 offer enhanced breathability compared to GENII™ and CONFIDENCE BE®, whilst being able to provide exceptional fluid handling capacity performance overall.

[0115] The moisture handling properties of examples 4, 6, 7, 10, GENII™ and CONFIDENCE BE® acquired and processed according to the BS EN 13726-1 standard are shown in Table 4 and Figure 5. This test is indicative of the water vapor moisture handling properties of adhesive compositions in direct contact with fluid. This test was performed to ascertain the moisture transmission and absorptive capacity of adhesive compositions in direct contact with fluid. The experimental set-up may be considered a proxy for scenarios requiring a relatively high volume of bodily fluid to be managed, including but not limited to sweat, wound exudate and excrement. Typical scenarios may include, but are not limited to, coverage of a highly exudating wound, performance of intense exercise, and29Ref: H16904WO / MZCduring an ostomy leakage scenario.

[0116] Table 4. Moisture handing properties (BS EN 13726-1 standard)

[0117] These data show that examples 4, 6, 7 and 10 can achieve improved moisture vapour transmission rate over GENII™. For instance, example 10 achieves a 2,092% improvement in moisture vapour transmission rate over GENII™. Example 10 also achieves a 127% improvement in moisture vapour transmission rate over CONFIDENCE BE®. These data also show that examples 4, 6, 7 and 10 can achieve improved fluid handling capacity over GENII™. For instance, example 10 achieves a 1,996% improvement in fluid handling capacity over GENII™ and a comparable fluid handling capacity when compared to CONFIDENCE BE®. This indicates that examples 4, 6, 7 and 10 offer enhanced breathability compared to GENII™ and CONFIDENCE BE®, whilst being able to provide exceptional fluid handling capacity performance overall.

[0118] The oxygen transmission rates of Example 10 and CONFIDENCE BE® were determined according to the ASTM F1927-20 standard. Samples were obtained as described above. The remaining polyethylene layer was removed. Thus, the tested sample comprised a layer of the adhesive composition laminated to a layer of the MED5712P moisture permeable backing. The oxygen gas transmission rate through each sample was determined in accordance with ASTM F1927-20 at a temperature of 37±2°C and a relative humidity of 19±5%.30Ref: H16904WO / MZC

[0119] The samples were mounted to create a membrane between two chambers. Each chamber was initially flushed with a carrier gas and then oxygen was flushed through the outer chamber. The sensor was then activated to detect the amount of oxygen that had permeated through the sample and measurements were taken over the course of several hours until the system had reached equilibrium.

[0120] Each sample was tested until the current transmission rate and transmission rates previously obtained was less than 1%.

[0121] Three replicates for each sample were tested to 100% oxygen with the exposed adhesive composition facing the oxygen. Results are quoted to 100% oxygen. The results are depicted in Table 5.

[0122] Table 5. Oxygen transmission data (ASTM F1927-20 standard)

[0123] The oxygen transmission data show that examples according to the present technology can obtain a mean increase in oxygen transmission rate of around 18,716 % when compared to conventional polyisobutylene-based adhesive compositions.

[0124] The present disclosure demonstrates that with the addition of various additives to a one-part polysiloxane adhesive system a balance of desirable properties can be achieved. In particular, embodiments of the present technology show that adhesive compositions based on one-part polysiloxane adhesives are 31Ref: H16904WO / MZCmore suitable in ostomy than adhesive compositions based on two-part polysiloxane adhesives in terms of having better moisture handling attributes and adequate shear resistance to support secondary medical devices.

[0125] It should be recognized that while the foregoing discussion of the various aspects of the disclosure has described specific sequences of steps necessary to perform the methods of the present disclosure, other sequences of steps may be used depending on the application. Specifically, additional steps may be added, and other steps deleted as being optional. Furthermore, the order of performance of certain steps may be permuted, and / or performed in parallel with other steps. Hence, the specific methods disclosed herein are merely exemplary of the broader methods of the disclosure.

[0126] It will be further appreciated that while certain steps and aspects of the various methods and apparatus described herein may be performed by a human being, the disclosed aspects and individual methods and apparatus are generally computerized / computer implemented. Computerized apparatus and methods are necessary to fully implement these aspects for any number of reasons including, without limitation, commercial viability, practicality, and even feasibility (i.e., certain steps / processes simply cannot be performed by a human being in any viable fashion).

[0127] While the above detailed description has shown, described, and pointed out novel features of the disclosure as applied to various embodiments, it will be understood that various omissions, substitutions, and changes in the form and details of the device or process illustrated may be made by those skilled in the art without departing from the disclosure. The embodiments described are to be considered in all respects only illustrative and not restrictive. The scope of the disclosure is, therefore, indicated by the appended claims rather than the foregoing description. All changes that come within the meaning and range of equivalence of the claims are embraced within their scope.

[0128] While various embodiments have been described above, it should32Ref: H16904WO / MZCbe understood by a person of ordinary skill in the art that the description has been presented by way of example only, and not limitation. Thus, the breadth and scope of the claims or a preferred embodiment should not be limited by any of the abovedescribed exemplary embodiments but should be defined only in accordance with the following claims and their equivalents.

[0129] When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

[0130] The invention may also broadly consist in the parts, elements, steps, examples and / or features referred to or indicated in the specification individually or collectively in any and all combinations of two or more said parts, elements, steps, examples and / or features. In particular, one or more features in any of the embodiments described herein may be combined with one or more features from any other embodiment(s) described herein.

[0131] Protection may be sought for any features disclosed in any one or more published documents referenced herein in combination with the present disclosure.

[0132] Although certain example embodiments of the invention have been described, the scope of the appended claims is not intended to be limited solely to these embodiments. The claims are to be construed literally, purposively, and / or to encompass equivalents.33Ref: H16904WO / MZC

Claims

[0133] CLAIMS1. An adhesive composition comprising:a. a polysiloxane adhesive;b. a reinforcing component;c. a plasticizing component; andd. an absorbing component.

2. The adhesive composition of claim 1 wherein the polysiloxane adhesive is a one-part adhesive and / or at least partially crosslinked.

3. The adhesive composition of any preceding claim wherein the polysiloxane adhesive has a solids content of about 100%.

4. The adhesive composition of any preceding claim wherein the polysiloxane adhesive constitutes about 30.0% to about 45.0% by weight of the total weight of the adhesive composition.

5. The adhesive composition of any preceding claim wherein the reinforcing component is selected from the group consisting of fumed silica, fumed alumina, colloidal silica, nano-clays, silicates, silane treated organic polymers, polymeric metal oxides, non-polymeric metal oxides, and any combination thereof.

6. The adhesive composition of any preceding claim wherein the reinforcing component is a fumed silica.

7. The adhesive composition of claim 6 wherein the fumed silica comprises: a SiO2 content of about 99%; and / or a specific surface area (BET) in the range of about 50.0 m2 / g to about 600.0 m2 / g; and / or a pH value in the range of about 3.5 to about 5.5; and / or a density in the range of about 150.0 kg / m3to about 200.0 kg / m3.34Ref: H16904WO / MZC8. The adhesive composition of any preceding claim wherein the reinforcing component constitutes about 1.0% to about 5.0% by weight of the total weight of the adhesive composition.

9. The adhesive composition of any preceding claim wherein the plasticizing component constitutes about 1.0% to about 6.5% by weight of the total weight of the adhesive composition.

10. The adhesive composition of any preceding claim wherein the plasticizing component is selected from the group consisting of silicone fluids, phthalates, phosphate esters, polyisobutylenes, fatty acid esters, polyalkylbenzenes, and any combination thereof.

11. The adhesive composition of any preceding claim wherein the plasticizing component is a hydroxyl terminated polysiloxane silicone fluid.

12. The adhesive composition of claim 11 wherein the hydroxyl terminated polysiloxane silicone fluid has a density of about 0.98 g / mL; and / or a viscosity <45 cSt; and / or a hydroxyl content of >3.8%.

13. The adhesive composition of any preceding claim wherein the absorbing component is selected from the group consisting of agar-agar, gelatine, locust bean gum, guar gum, pectin, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, hydroxypropyl cellulose, alginate, carrageenan, xanthan gum, tragacanth gum, konjac gum, starch, chitosan, sodium polyacrylate, potassium polyacrylate, and any combination thereof.

14. The adhesive composition of any preceding claim wherein the absorbing component comprises, consists of or consists essentially of a combination of (i) carboxymethyl cellulose and (ii) gelatine.

15. The adhesive composition of claim 14 wherein the carboxymethyl cellulose comprises a D80 particle size distribution of approximately 75 microns; and / or a sodium content in the range of about 6.0% to about 9.0%; and / or a viscosity35Ref: H16904WO / MZCfor a 1.0% solution at 25 °C in the range of about 10.0 mPa.s to about 5000.0 mPa.s.

16. The adhesive composition of claim 14 or claim 15 wherein the gelatine comprises a particle size in the range of about 8.0 mesh to about 200.0 mesh; and / or a Bloom strength in the range of about 30.0 g Bloom to about 300.0 g Bloom; and / or a pH value in the range of about 4.5 to about 6.0.

17. The adhesive composition of any preceding claim wherein the absorbing component constitutes about 45.0% to about 75.0% by weight of the total weight of the adhesive composition.

18. The adhesive composition of any preceding claim comprising a complex shear modulus for 0.001% strain at 25°C in the range of about 1.0x105Pa to about 1.0x107Pa.

19. A base plate for an ostomy device, the base plate comprising a layer of the adhesive composition of any preceding claim, the layer of adhesive composition having a first surface and a second surface, wherein a backing layer is laminated to the first surface.

20. The base plate of claim 19 wherein the backing layer is moisture permeable.

21. The base plate of claim 19 or claim 20 having an oxygen gas transmission rate therethrough from about 10,000 cm3 / m2 / 24h to about 30,000 cm3 / m2 / 24h when performed in accordance with ASTM F1927-20 at a temperature of 37 °C and a relative humidity of 19 %.

22. The base plate of claim 20 or claim 21 further comprising a release liner, wherein the release liner is laminated to the second surface of the layer of adhesive composition.

23. An ostomy device comprising the base plate of any of claims 19 to 22 and a pouch for collecting stomal discharge, wherein the base plate and the pouch are connected or connectable to one another.36Ref: H16904WO / MZC

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