Ostomy appliance wafer with controlled peel force, permeability, and moisture absorption

Abstract

An ostomy appliance wafer has a skin facing layer of adhesive applied to a proximal side of a film layer to define a proximal skin facing surface of the ostomy appliance wafer, and the skin facing layer of adhesive has a thickness in a range between 25 to 200 micrometers.

Claims

1. An ostomy appliance wafer comprising: a backing layer having a distal side that defines a distal wafer surface of the ostomy appliance wafer, where the distal wafer surface is configured to receive a waste collection pouch; a first layer of adhesive applied to a proximal side of the backing layer; a film layer applied to the first layer of adhesive; and a skin facing layer of adhesive applied to a proximal side of the film layer and defining a proximal skin facing surface of the ostomy appliance wafer; wherein the skin facing layer of adhesive has a thickness in a range between 25 to 200 micrometers; wherein the skin facing layer of adhesive has a moisture permeability above 100 g/m.sup.2/24 h.

2. The ostomy appliance wafer of claim 1, wherein the backing layer and the film layer are formed of the same material.

3. The ostomy appliance wafer of claim 1, wherein the film layer is moisture permeable.

4. The ostomy appliance wafer of claim 1, wherein the film layer has a moisture permeability above 1000 g/m.sup.2/24 h.

5. The ostomy appliance wafer of claim 1, wherein the film layer is liquid impermeable.

6. The ostomy appliance wafer of claim 1, wherein the film layer is one of a non-woven layer and a foamed film layer.

7. The ostomy appliance wafer of claim 1, wherein a thickness of the film layer is in a range between 10 to 50 micrometers.

8. The ostomy appliance wafer of claim 1, wherein the skin facing layer of adhesive has a water absorption capacity of less than 8%.

9. The ostomy appliance wafer of claim 1, wherein the first layer of adhesive has a water absorption capacity of more than 15%.

10. The ostomy appliance wafer of claim 1, wherein the first layer of adhesive comprises moisture absorbent particles.

11. The ostomy appliance wafer of claim 1, wherein the first layer of adhesive comprises moisture absorbent particles selected from the group consisting of salts, hydrocolloids, microcolloids, and super absorbers.

12. The ostomy appliance wafer of claim 1, wherein the first layer of adhesive comprises moisture absorbent particles in a range between 5 to 30% w/w.

13. The ostomy appliance wafer of claim 1, wherein the skin facing layer of adhesive and the film layer combine to provide the ostomy appliance wafer with a measured peel force of less than 8 N force with the film layer having a moisture permeability above 1000 g/m.sup.2/24 h, and wherein the first layer of adhesive has a water absorption capacity of more than 15%.

14. An ostomy appliance wafer comprising: a backing layer having a distal side that defines a distal wafer surface of the ostomy appliance wafer, where the distal wafer surface is configured to receive a waste collection pouch; a first layer of adhesive applied to a proximal side of the backing layer; a film layer applied to the first layer of adhesive; and a skin facing layer of adhesive applied to a proximal side of the film layer and defining a proximal skin facing surface of the ostomy appliance wafer; wherein the skin facing layer of adhesive has a thickness in a range between 25 to 200 micrometers; wherein the skin facing layer of adhesive has a water absorption capacity of less than 8%.

15. An ostomy appliance wafer comprising: a backing layer having a distal side that defines a distal wafer surface of the ostomy appliance wafer, where the distal wafer surface is configured to receive a waste collection pouch; a first layer of adhesive applied to a proximal side of the backing layer; a film layer applied to the first layer of adhesive; and a skin facing layer of adhesive applied to a proximal side of the film layer and defining a proximal skin facing surface of the ostomy appliance wafer; wherein the skin facing layer of adhesive has a thickness in a range between 25 to 200 micrometers; wherein the first layer of adhesive has a water absorption capacity of more than 15%.

16. An ostomy appliance wafer comprising: a backing layer having a distal side that defines a distal wafer surface of the ostomy appliance wafer, where the distal wafer surface is configured to receive a waste collection pouch; a first layer of adhesive applied to a proximal side of the backing layer; a film layer applied to the first layer of adhesive; and a skin facing layer of adhesive applied to a proximal side of the film layer and defining a proximal skin facing surface of the ostomy appliance wafer; wherein the skin facing layer of adhesive has a thickness in a range between 25 to 200 micrometers; wherein the skin facing layer of adhesive and the film layer combine to provide the ostomy appliance wafer with a measured peel force of less than 8 N force with the film layer having a moisture permeability above 1000 g/m.sup.2/24 h, and wherein the first layer of adhesive has a water absorption capacity of more than 15%.

Description

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(1) The invention is now explained more in detail with reference to the drawings of FIGS. 1 to 3 showing preferred embodiments of the invention.

(2) FIG. 1 illustrates a side view of the construction 1 of a known layered adhesive construction containing a backing layer (11), an intermediate layer of adhesive (12) and a skin facing layer of adhesive (13). No film is separating the two layers of adhesive.

(3) FIG. 2 illustrates a side view of the construction 2 of an embodiment according to the invention containing a backing layer (21), an intermediate layer of adhesive (22), a skin facing layer of adhesive (23) and a film layer (24).

(4) FIG. 3 shows a diagram illustrating the peel force in different adhesive constructions and adhesive compositions.

MATERIALS AND METHODS

(5) Methods

(6) Determination of Water Absorption

(7) In order to get better correlation between measured water absorption and actual performance in a humanlike environment, a modified version of the ISO 62 standard was used: Pieces of adhesive of 1?25?25 mm.sup.3 were fastened on a piece of glass using double sided adhesive and the constructs were immersed in saline water (0.9% NaCl in demineralised water) at 32? C. After 24 hours the samples were removed and carefully dripped dry and weighed. The change in weight was recorded and reported as weight gain in percent of the original dry weight of the adhesive. In the following we call this value w.sub.24h

(8) Determination of Moisture Vapour Transmission Rate (MVTR)

(9) MVTR was measured in grams per square meter (g/m.sup.2) over a 24 hours period using an inverted Paddington cup method (British Pharmacopoeia, 1993, Addendum 1996, page 1943. HMSO London): A container or cup being water and water vapour impermeable having an opening was used. 20 ml saline water (0.9% NaCl in demineralised water) was placed in the container and the opening was sealed with the test adhesive film. The container, with a duplicate, was placed into an electrically heated humidity cabinet and the container or cup was placed up side down in a way that the water was in contact with the adhesive. The cabinet was maintained at 37? C. and 15% relative humidity (RH). After about an hour, the containers were considered to be in equilibrium with the surroundings and were weighed. 24 h after the first weighing, the containers were weighed again. The weight difference was due to evaporation of vapour transmitted through the adhesive film. This difference was used to calculate Moisture vapour transmission rate or MVTR. MVTR was calculated as the weight loss after 24 h divided by the area of the opening in the cup (g/m.sup.2/24 h). If the adhesive film could not support the weight of the water, a supporting film with very high permeability was used as support.

(10) Determination of G*

(11) The parameter G* or complex modulus as defined in Dynamics of polymeric liquids, Vol. 1, sec. ed. 1987, Bird, Armstrong and Hassager, John Wiley and Sons inc., was used as a measure of the hardness of an adhesive. To avoid any confusion, note that G* in here means the absolute value of the complex G*. G* at 32? C. and 1 Hz was measured as follows: A plate of un-foamed adhesive material was pressed into a plate of 1 mm thickness. A round sample of 25 mm in diameter was cut out and placed in a RheoStress RS600 rheometer from Thermo Electron. The geometry applied was parallel plates 25 mm and the deformation was fixed at 1% to ensure that measurements were in the linear regime. The measurement was carried out at 32? C.

EXAMPLE 1

(12) In example 1 the decrease in peel force was measured in different adhesive systems with and without the film layer.

(13) 25?100 mm adhesive strips for peel test were produced in 1 mm thickness. In Table 1 below the adhesive construction is seen. The intermediate adhesive layer formulation and the skin facing layer formulation in a construction were the same.

(14) TABLE-US-00001 TABLE 1 Cons. Soft adhesive A Soft adhesive B Standard adhesive C 1 Backing layer 40 my Backing layer 40 my Backing layer 40 my Intermediate adh. layer 760 my Intermediate adh. layer 760 my Intermediate adh. layer 760 my Film layer none Film layer none Film layer none Skin facing adh. layer 200 my Skin facing adh. layer 200 my Skin facing adh. layer 200 my 2 Backing layer 25 my Backing layer 25 my Backing layer 25 my Intermediate adh. layer 760 my Intermediate adh. layer 760 my Intermediate adh. layer 760 my Film layer 15 my Film layer 15 my Film layer 15 my Skin facing adh. layer 200 my Skin facing adh. layer 200 my Skin facing adh. layer 200 my

(15) By 1 my is meant 1 ?m. The data in Table 1 indicate the thickness of the layer.

(16) For each adhesive system two constructions were made.

(17) Construction 1 was a 1 mm thick wafer with a 40 ?m soft polyurethane top film (Bioflex 180 from Scapa Medical). The intermediate adhesive layer and the skin facing adhesive layer were simply adhered together in a way that they acted as one 960 ?m thick adhesive.

(18) Construction 2 was a 1 mm thick wafer with a 25 ?m soft polyurethane backing layer (Bioflex 180 from Scapa Medical) and a 15 ?m soft polyurethane film layer (Bioflex 180 from Scapa Medical) that divided the adhesive in two. The skin facing adhesive layer was 200 ?m and the intermediate adhesive layer was 760 ?m.

(19) In construction 1 and 2 the total thickness of the film layer(s) was 40 ?m (40 or 25+15 ?m).

(20) Three types of adhesives were tested. The intermediate adhesive layer and the skin facing adhesive layer were the same in the respective construction.

(21) By % is meant % (w/w).

(22) ASoft adhesive system based on

(23) TABLE-US-00002 TABLE 2 Soft adhesive system A % PPO ACS003, Kaneka 96.9 Crosslinker, CR600, Kaneka 3.0 Catalyst, Pt-VTSC 0.09

(24) The materials were mixed manually in a cup for 1 minute and cured 30 minutes at 90? C. in a mould giving the desired construction. 25?100 mm adhesive strips for peel test were cut out from the wafer. The desired film(s) were chosen for construction 1 and 2.

(25) BSoft adhesive system based on

(26) TABLE-US-00003 TABLE 3 Name Soft adhesive Trade name of system B (Chemical name) Supplier % Levamelt 700, 22.5 KGy Lanxess 20 Levamelt 500, 16.6 KGy Lanxess 11 Levamelt 700 Lanxess 6 Oppanol B12 BASF 8 Poly Glycol B01/120 Clarient 47 Kristalex 100 Eastman 8 BHT (2,6-di-tert.-butyl-4-metylfenol) Sigma 0.3

(27) The adhesives were produced by Z-blade mixing the materials at 120? C. for 1 hour. The gamma radiated materials had to be mixed first with the glycol in order to plasticise the system. Construction of 1 and 2 were made in a heat press similar to the procedure for adhesive C.

(28) CStandard hydrocolloid adhesive system (25% Kraton D-1161, 35% Arkon P90 resin, 5% dioctyl adipate plasticiser and 35% Blanose 9H4X, Aqualon hydrocolloid) was used as the reference adhesive.

(29) Construction 1 was obtained as the following: All raw materials were blended in a Z-blade mixer equipment at 140? C. for 1 hour. The wafer of a 1 mm thick plate was produced by heat pressing at 90? C. for 10 seconds in a 1 mm deep mould (1?150?150 mm).

(30) Construction 2 was produced by heat pressing the adhesive composition into 200 ?m and 760 ?m respectively in between two siliconised films. The pressing between two siliconised films makes it possible to remove the siliconised film without destroying the adhesive. Suitable siliconised film is a 110 my PP liner with silicone coating 1808 from Huhtamaki. The desired construction with the 25 ?m backing layer and the 15 ?m film layer is obtained by laminating the materials by heat pressing in 10 seconds at 90? C. in a 1 mm deep mould. Both constructions were covered with a siliconised protective film prior to heat pressing. The construction is then cut into 25?100 mm strips ready for testing.

(31) The peel measurements were performed on an Instron 5564 with a 100 N load cell at 100 m/min., 25? C. Peel substrate was paper for the soft adhesive constructions and steel for the hydrocolloid adhesive. The paper was fixated to a solid surface with double layered adhesive tape. As a paper peel substrate newspaper is used. Three samples were tested for each construction.

(32) Results

(33) FIG. 3 shows a diagram illustrating the peel force in different adhesive constructions and adhesive compositions. The peel force was measured as AVG Peel Load [N].

(34) A significant peel drop in soft adhesive A and B, going from a peel front of 1,000 ?m to 200 ?m was seen. A reduction in peel force was obtained without compromising other adhesive properties such as shear, water handling and initial tack. The typical way to reduce the peel force is to reformulate the adhesive in a way that it is easy to remove. When using the stiffer adhesive C, no change in peel force is seen, when adding a film layer, as the stiffer adhesive rather than the film layer tend to control the peel force. In that case the presence of a film layer close to the skin does not affect the peel force.

(35) Reduced extension of the adhesive construction 2 was seen in case of the soft adhesive systems using adhesive A or adhesive B. This was due to the lowering of the peel force. No reduction in extension was seen in adhesive C as the peel force was not reduced.

(36) When lowering the peel force of the adhesive shown in the example, less stretch is also obtained for the adhesive during removal of the adhesive from the substrate. This effect is beneficial for the handling issues as it is desirable to remove the adhesive without an excessive stretch, but yet retaining the security during wear with a soft comfortable adhesive wafer construction according to the invention.