NZ712149B2 - High barrier elastomer fecal catheter or ostomy pouch - Google Patents

Abstract

Disclosed is an odor barrier material for a fecal catheter, a fecal pouch, or an ostomy pouch comprising, a elastomer and an antiblocking agent, such as a zeolite or nanocomposite or selected from a group of essentially inorganic fillers, including silica, talc, clay, and mica, wherein the odor barrier material comprises a surface having an arithmetic mean surface roughness (Ra) not less than 0.1 micron. ier material comprises a surface having an arithmetic mean surface roughness (Ra) not less than 0.1 micron.

Description

HIGH BARRIER ELASTOMER FECAL CATHETER OR OSTOMY POUCH The present application is a divisional application from New Zealand Patent Application No. 616754, the entire disclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION The present invention relates to an odor barrier material for a fecal catheter, a fecal pouch, or an ostomy pouch.

BACKGROUND OF THE INVENTION Fecal catheters have occasionally been criticized for the transmission of fecal odor through the tubular walls.

A possible cause of the poor odor barrier is the silicone material of which these devices are composed. The odor r of silicone is known to be one of the worst among polymer materials. For example, the oxygen transmission rate of silicone has been reported to be 775,000 cc mil/m2/day. ore, a 20 mil thick silicone catheter is about 3 orders of magnitude worse than a ly used ostomy film having a transmission rate of 50 cc/m2/day or less.

Another possible explanation for ne fecal catheter having poor odor r is that the extruded silicone utilized in such devices is relatively rough and as a result could trap fecal components. The contours of the spots ng the fecal al provide substantial surface area, through which odor is transmitted.

The combination of high odor transmission rate and large surface area contributes to the poor odor barrier characteristics of the silicone used in fecal catheters.

It would be desirable to develop a material to be used in a fecal er that has the desirable characteristics of silicone while providing an odor r substantially better than that of silicone.

It would be desirable to provide an odor barrier polymer having these characteristics.

The discussion of the background to the invention included herein including nce to documents, acts, materials, devices, articles and the like is included to n the context of the present invention. This is not to be taken as an admission or a suggestion that any of the material referred to was published, known or part of the common general knowledge in New Zealand or in any other country as at the priority date of any of the claims.

SUMMARY OF ION Viewed from an aspect of the present invention, there is provided an ostomy pouch comprising an odor barrier material, the ostomy pouch comprising: (i) a thermoplastic elastomer ed from a group including a styrenic block copolymer, a thermoplastic vulcanizate, and a polyolefin elastomer; (ii) an odor barrier modifier selected from polyisobutene, polybutene, or an organoclay; and (iii) an antiblocking agent ed from a group of substantially nic fillers, including silica, talc, clay, and mica, said odor barrier material having an arithmetic mean surface roughness Ra not less than 0.1 µm.

Viewed from another aspect of the present invention, there is provided an odor barrier material useful for an ostomy pouch or fecal catheter, the odor barrier material comprising: an elastomer selected from a group ing ne, polyurethane, styrenic block copolymer, plastic vulcanizate and polyolefin elastomer; and a nanocomposite filler material coated on or present within said elastomer as to provide an odor barrier, said odor barrier material having a Shore A hardness of not more than 60, said odor barrier al having an arithmetic mean surface roughness Ra not less than 0.1 µm.

Viewed from another aspect of the present ion, there is provided a fecal catheter comprising the odor barrier material as disclosed herein, wherein said catheter does not crack upon flexing.

View from another aspect of the t invention, there is provided a fecal catheter comprising the odor barrier material as disclosed herein, wherein said catheter is extruded and may be converted both by welding and adhesive bonding.

Viewed from yet another aspect of the present invention, there is provided an odor barrier material for an ostomy pouch or fecal catheter tube, the odor barrier material comprising: an elastomer substrate comprising a zeolite containing coating on said elastomer ate; said elastomer and zeolite forming a soft er tube having a Shore A hardness of not more than 60, said odor barrier or pouch material having an arithmetic mean e roughness Ra not less than 0.1 µm.

Viewed from still another aspect of the t invention, there is provided a fecal catheter comprising an odor barrier al, the fecal catheter comprising: a silicone tube; at least one layer of nanocomposite coating on said tube; and at least one layer of a silane coupling agent, said coated tube having an oxygen transmission rate of no more than 20,000 day and a surface having an arithmetic mean surface roughness Ra not less than 0.1 µm.

Viewed from a further aspect of the present invention, there is provided an odor barrier material for a fecal catheter or ostomy pouch, the odor barrier material sing; an elastomer selected from a group including silicone, polyurethane, styrenic block copolymer, thermoplastic vulcanizate and polyolefin elastomer; and an antiblocking agent, n the ocking agent is selected from the group consisting of inorganic fillers, including silica, talc, clay, and mica, and any combination thereof, that s a rough surface to prevent ng, wherein said surface has an arithmetic mean surface roughness Ra not less than 0.1 µm.

Where the terms “comprise”, “comprises”, “comprised” or “comprising” are used in this specification ding the claims) they are to be reted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other features, integers, steps or components, or group thereto.

DESCRIPTION OF THE INVENTION Thermoplastic elastomer (TPE) or curable elastomer is well known for use in medical devices. However, these elastomers are not known to exhibit high odor barrier properties. The present invention is the modification of elastomer to achieve a high odor barrier while maintaining its softness, ability for post extrusion converting (welding and bonding) and non-blocking characteristics.

One embodiment of the present invention related to single layer of catheter made from a high barrier elastomer such that the odor r measured by oxygen transmission rate per ASTM D3985 is not more than 50,000 cc mil/mzlday at 23°C, or more preferably not more than 5,000 cc mil/mZ/day. Such a catheter is at least 10 times better in odor barrier than the silicone catheter.

US. Pat. No. 6,946,522, 7,056,971, and 7,060,753 disclosed the use of a liquid polyisobutene oil plasticizer to improve the gas barrier of the TPE. However, these formulations, especially when targeting a soft elastomer, i.e., Shore A less than 60, s a blocking issue in which the surface of TPE er seals against each other upon folding and packaging. The use of a higher amount of oil plasticizer would allow a softer TPE, but it comes with an adverse effect in an oily surface, resulting in poor post-extrusion converting (welding and bonding). In addition, the TPE based on an olefin block copolymer (OBC, such as InfuseTM made by Dow) was not disclosed. Although common approaches exist to minimize the blocking, including adding l oil or slip additives. These approaches; however, have drawbacks in that they prevent the parts from being further converted into a fecal catheter due to their adverse effects on the surface bonding. US. Pat. No. 7,629,406 disclosed the use of an organoclay at a concentration less than 4% to improve the barrier properties of high density polyethyelene (HDPE). However, the use of organoclay in a TPE was not mentioned with a Shore A hardness not more than 60, or preferably not more than 50. r ment of the present invention is related to a fecal catheter, having a Shore A hardness not more than 60 and an oxygen transmission rate not more than 2,500 day or preferably not more than 1,000 cc/mzlday, comprising (1) a thermoplastic elastomer, (2) odor barrier er, and (3) an antiblocking agent of at least 0.1%, n thermoplastic elastomer is selected from the group consisting of a styrenic block copolymer, a thermoplastic izate, or a polyolefin elastomer, and wherein odor r modifier is ed from the group consisting of polyisobutene, polybutene, or an organoclay, and n the antiblocking agent is selected from the group consisting of an essentially inorganic fillers, such as silica, talc, clay, mica, etc. and blends thereof. It is noted organoclays can be used in one embodiment as both the odor barrier modifier and as the antiblocking agent.

Organoclays include montmorillonite clay, smectite clay, intercalated clay, nanoclay, or a mixture of above. Organoclay described in this invention includes montmorilionite clay, made by Nanocor, which is the most common member of the smectite clay family. clay may consist of nanoclay with a unique morphology such that one dimension is in the nanometer range. in addition, organociay is preferred to be intercalated with an organic intercaiant resulting in a clay-chemical complex wherein the clay gallery spacing has increased due to the process of surface modification. Under the proper conditions of temperature and shear, an alate is capable of exfoliating in a resin matrix. Optionally, the following additives can be used to facilitate the manufacturing of catheter extrusion, including melt viscosity modifier, ier, detackifier, cizer, etc.

Styrenic block copolymer (SBC) based thermoplastic mer includes styrene-isoprene-styrene (SIS), styrene-butadiene—styrene (SBS), styrene- etheyiene/butylene-styrene , styrene-etheylene/propylene-styrene (SEPS), and blends thereof. Thermoplastic vulcanizate (TPV) includes a blend of curable rubber and a efin (i.e., PP or PE, homopolymers and copolymers). Curabie rubbers include EPDM, EP rubber, santoprene, etc. A polyolefin elastomer includes an olefin block copolymer (080), such as infuse made by Dow, where a crystalline phase of a olefin block copolymer acted as hard blocks, and the amorphous block copolymer acted as soft blocks within the same r matrix. The ing is a summary of odor barrier as measured by oxygen transmission rate at 23°C per ASTM D3985: Table 1 - Odor r Comparison of Various Elastomers without Organoclays or zeolites Silicone sec"w/ 880 w/ polyisobute polyisobutene ne and Organoclay OTR, cc/mzlday, mil thick wall, ASTM D3985 Very poor, Poor, 1 Better, Good, not Barrier. detectable detectable detectable detectable able detectable for 8 ISO 8670-3 in 10 in 60 in 60 in 60 in 120 hrs minutes minutes minutes minutes minutes When antiblocking agent. at least 0.1% or more preferably more than 0.5%. was added to a high barrier elastomer formulation containing a SBC thermoplastic elastomer and a liquid poiyisobutene, an odor barrier in the range of around 1000 cc/mzlday was achieved for making a non-blocking fecal catheter. This level of odor barrier improvement was confirmed by an onion test per lSO 8670-3 such that the onion odor breakthrough was longer than 120 minutes. Additional barrier improvement was seen in fecal catheter made from PTE ning a SBC thermoplastic elastomer, a liquid poiyisobutene, an organoclay. In this example, onion odor breakthrough was longer than 8 hours. The results of both oxygen r and onion r were shown in Table 1.

Another embodiment of the present invention is a fecal catheter based on a multilayer structure, wherein at least one layer is selected from a high barrier elastomer described above without any antiblocking agent, and at least another skin layer is selected from the group ting of (1) same high barrier elastomer described above with at least 0.1 % of antiblocking agent, or an elastomer alloy with or without the use of antiblocking agent. An elastomer alloy is defined as a blend of two polymer matrixes which are incompatible in a molecular level. The age of antiblocking agent is to impart a rough surface so that the catheter is not blocking.

The age of an elastomer alloy is that the incompatibility in a molecular level s a roughness on the catheter surface, giving rise to a non-blocking catheter.

In addition, common materials to add for an elastomer alloy include, but not limited to. thermoplastic polyurethane (TPU). Due to a more polar structure in TPU, the subsequent converting of an mer alloy is easier. Since the majority of the catheter structure is provided by a high barrier mer, the odor barrier and the softness is maintained based on the disclosure above. Because both the center layer and the skin layer are elastomers based, the adhesion between the layers of a fecal er is sufficiently good.

Besides the addition of anti-blocking agent, cold sing conditions can be utilized to e a rough surface of the catheter wall so that the catheter is not blocking. The effect of anti-blocking agent and/or cold processing conditions is a rough surface that could be characterized by surface roughness using a non-contact surface structure analyzer, such as Scanning White Light interferomtry (SWLI), Atomic Force Microscopy (AFM), etc. A non-contact imaging surface ure analyzer based on SWLI is made by Zygo NewView 7300. A non-contact atomic force microscopy can be made by FEI. A typical ter that has been used to quantify the y of a surface topography is the surface roughness, which is represented by the arithmetic mean value, Ra. In this invention disclosure, a rough surface with Ra not less than 0.1 pm or preferably not less than 1 pm when antiblocking agent is used with or without a cold processing temperature. resulted in a non-blocking fecal catheter.

An important characteristic about the formulation bed in this invention is its ability to be post-extrusion converted, both by welding and adhesive bonding.

Greater than 5 Min adhesive strength and heat weld strength was achieved.

Another embodiment of the present invention is d to the use of organoclays and/or zeolites to improve the odor barrier of the elastomer catheter.

For example, a single layer of er can be made from an organoclay-containing elastomer selected from the group consisting of silicone, polyurethane, styrenic block copolymer, thermoplastic vulcanizate, or polyolefin elastomer with a Shore A hardness not more than 60, or more preferably not more than 50.

The use of mposite (nanoclays) fillers to improve the odor barrier is not new. The on of nanocomposite fillers creates the tortuous path for the odor causing compounds; thus improving the odor barrier for the substrate. There are various nanocomposite containing coating, ves, or polymers marketed by various companies, such as Nanocor, Nanoresin, rn Clays, Nano-X, lnmat, etc. Since nanocomposites are mostly clay based, it is vely rigid. Therefore, the challenges of using nanocomposite fillers in FMS application are two fold, (1) the difficulty in the wetting and adhesion of the nanocomposite fillers or coating onto the silicone tubing, and (2) the odor barrier property upon flexing. ore, the uniqueness of this ion is the formulation of a soft tube with a completely covered, and/or relatively uniformly dispersed nanocomposite ning catheter which would not crack upon flexing. Such a soft nanoclay-containing catheter is characterized with a Shore A hardness not more than 60, or more preferably not more than 50.

Another embodiment of the present invention is related to single layer of catheter made from a zeolite-containing elastomer selected from the group consisting of ne, polyurethane, styrenic block copolymer, thermoplastic vulcanizate, or polyolefin elastomer with a Shore A hardness not more than 60, or more preferably not more than 50.

The addition of zeolite creates the tortuous paths and sites to adsorb the odor causing compounds; thus improving the odor barrier for the substrate. There are various zeolites marketed by various companies, such as UOP. Since zeolites are hard fillers, they produce ty when used. Therefore, the challenges of using zeolites in FMS application are two fold, (1) the difficulty in the g and adhesion of the e coating onto the silicone tubing, and (2) the odor barrier property upon flexing. Therefore, the uniqueness of this invention is the ation of a soft tube with relatively uniform zeolite-containing elastomeric catheter which would not crack upon flexing. Such a soft zeolite—containing er is characterized with a Shore A hardness not more than 60, or more preferably not more than 50.

Another embodiment of the present invention is related to an organoclay— ning coating onto an elastomer substrate selected from the group ting of ne, polyurethane, styrenic block copolymer, thermoplastic vulcanizate, or polyolefin elastomer with a Shore A hardness not more than 60, or more preferably not more than 50.

Another embodiment of the present invention is d to a zeolite-containing coating onto an elastomer substrate selected from the group consisting of silicone, polyurethane, styrenic block copolymer, plastic izate, or polyolefin elastomer with a Shore A hardness not more than 60. or more preferably not more than 50.

A series of experiments were conducted as described below. A total of four different nanocomposites were evaluated, two from Southern Clay and two from Nanocor. Two types of coating matrix were used. silicone and polyurethane. The ing is a summary of these findings: Exp. #1: Silicone coating consisting of nanocomposites: 2.5% of the following nanocomposites were added into a two—part silicone made by Nusil 6350, including (1) Southern Clay Cloisite Na+, Hydrated Aluminum Silicate, (2) Southern Clay Cloisite 15A, Ammonium salts with Bentonite, (3) Nanocor 1.30E (Octadecyl ammonium surface abilized montmorillonite), and (4) Nanocor 1.34 TCN (methyl, bis hydroxyethyl octadecyl ammonium e compatabilized montmorillonite).

The two-part silicone was applied onto the silicone er as a coating. and was then heat cured at 130 deg C for 30 minutes. The coated catheter was then tested for onion odor barrier per ISO 8670-3:2000. About 5 grams of onion was chopped and filled inside a 12 cm long coated ne tubing (i.e., catheter).

Nanocomposite None C101 si te Cloisite Nanocor Nanocor NA+ 15A [.30E 1.34TCN ------Coating Matrix, Silicone Silicone Silicone Silicone Silicone Substrate, Silicone Silicone Silicone Silicone Silicone Dow g C6-135 - As can be seen, the addition of 2.5% nanocomposites in a silicone coating improves the onion odor barrier in the silicone tubing. The control with a silicone coating had an onset of onion odor outside of the closed ne tubing at around 5 minutes. This is about the same as the silicone tube without any coating. After a silicone coating consisting of 2.5% nanocomposites was applied onto a silicone tube, the onset of the onion odor was extended to 45 — 90 minutes.

Exp. yurethane coating consisting of nanocomposites, without : 2.5% of the following nanocomposites were added into a two-part polyurethane made by Smooth—On, Vytaflex 30. including (1) Southern Clay Cloisite Na+, ed Aluminum Silicate. (2) Southern Clay te 15A, Ammonium salts with Bentonite. (3) Nanocor 1.30E (Octadecyl ammonium surface compatabilized montmorillonite), and (4) Nanocor 1.34TCN (methyl, bis hydroxyethyl octadecyl ammonium surface compatabilized montmorillonite).

The rt polyurethane was applied onto the silicone catheter as a coating, and was then room ature cured for 6 hours. The coated catheter was then tested for onion odor barrier per ISO 8670-3:2000. About 5 grams of onion was d and filled inside a 12 cm long coated silicone tubing (i.e., er).

Nanocomposite None Cloisite Cloisite 15A Nanocor Nanocor NA+ 1.30E l 34TC‘N Coating Matrix, ethane Polyurethane Polyurethane Polyurethane -olyurethane Vytaflex 30 rPimer, Dow Coming 1200 Substrate, Silicone S-iliconeS-ilicone Silicone Silicone Dow Corning C6- Smell As can be seen, the addition of 2.5% nanocomposites icantly improves the onion odor r. The control with a ethane coating, but without any nanocomposites, was able to extend the onset of onion odor outside of the closed silicone tubing from 5 minutes to 30 minutes. After a polyurethane coating consisting of 2.5% nanocomposites was applied onto a silicone tube, the onset of the onion odor was extended to 6 — 12 hours. Despite of the odor barrier ement, the coating adhesion was poor.

Exp. #3: Polyurethane coating consisting of nanocomposites, with primer: The same set of experiment as Exp. #2 was repeated with the use of a silane primer, Dow Coming 1200. The same level of onion odor improvement was observed. That is, after a polyurethane coating consisting of 2.5% nanocomposites was applied onto a silicone tube primed with a silane, the onset of the onion odor was extended from 30 minutes in the control without any nanocomposites to 6 — 12 hours. The polyurethane coating stuck well to the silicone tube, and was able to resist the flex.

Nanocomposite None Cloisite Cloisite 15A Nanocor Nanocor NA+ 1.3013 1.34TCN Coating Matrix, Polyurethane Polyurethane ethane Polyurethane Polyurethane Vytaflex 30 Primer, Yes Yes Yes Yes Yes Dow Coming 1200 Substrate, Silicone Silicone Silicone Silicone Silicone Dow g C6- Smell Exp. #4: mposites in a silicone slab: 2% of Nanocor 1.30E was added to make into a 1 mm thick (Le, 40 mil) silicone gel slab, Nusil 6350. Onion barrier was compared on silicone slab with and without the nanocomposite per ISO 8670-32000. 1 mm thick silicone slab without 1 mm thick silicone slab with nanocompositcs (control) 2% Nanocor 1.30E As a result, the addition of 2% of Nanocor 1.30E improved the onion odor barrier of the silicone slab from 5 s to about 60 minutes.

Another ment of the present invention is an improved odor r fecal catheter, having a Hardness of less than Shore A 60, comprising at least (a) one layer of a silane coupling agent, and (b) at least one layer of nanocomposite coating.

This formulation, when applied onto a silicone fecal catheter, would result in an oxygen transmission rate no more than 20,000 cc/m2/day, or preferably, no more than 10,000 cc//m2/day, or more preferably no more than 5,000 cc/m2/day. A silicone tube without the use of silane coupling agent and without the nanocomposite coating has an oxygen permeation rate of around 37,500 day. A silicone with the nanocomposite coating, but without the silane coupling agent, has an oxygen permeation rate of close to 30,000 — 35,000 cc/m2/day due to the lack of bonding.

Alternatively, the same ation can be applied onto a thermoplastic elastomer (TPE) or a polyurethane tubing (PU), having a Hardness of less than Shore A 60. such that the gas barrier is improved to no more than 25,000 cc/m2/day, or preferably, no more than 10,000 cc/m2/day, or more ably no more than 5,000 cc/m2/day.

The materials described in this invention can be used as a fecal catheter. A fecal pouch is commonly connected to a fecal catheter in use. The same materials described for fecal catheter were used to make a fecal pouch. Similar odor r characteristics against oxygen transmission and onion odor shown in Table 1 were obtained in the lab. Thus, besides a fecal catheter, the same material construction could be used for an ostomy pouch.

Claims (15)

The claims defining the invention are as follows:

1. An ostomy pouch comprising an odor barrier material, the ostomy pouch comprising: 5 i) a thermoplastic elastomer selected from a group including a styrenic block copolymer, a thermoplastic vulcanizate, and a polyolefin elastomer; ii) an odor barrier modifier selected from polyisobutene, polybutene, or an organoclay; and 10 iii) an antiblocking agent selected from a group of substantially inorganic fillers, including silica, talc, clay, and mica, said odor barrier material having an arithmetic mean surface roughness Ra not less than 0.1 µm.

2. An odor barrier material useful for an ostomy pouch or fecal er, the 15 odor barrier material sing: an elastomer selected from a group including silicone, polyurethane, ic block mer, plastic vulcanizate and efin elastomer; and a nanocomposite filler material coated on or present within said 20 elastomer so as to provide an odor barrier, said odor barrier material having a Shore A hardness of not more than 60, said odor barrier material having an arithmetic mean surface roughness Ra not less than 0.1 µm. 25

3. A fecal catheter comprising the odor barrier material of claim 2, wherein said catheter does not crack upon flexing.

4. A fecal catheter comprising the odor barrier material of claim 2, wherein said catheter is extruded and may be ted both by welding and adhesive 30 bonding.

5. An odor barrier material for an ostomy pouch or fecal catheter tube, the odor barrier material comprising: an elastomer substrate comprising a zeolite ning coating on said 35 elastomer substrate; said elastomer and e forming a soft er tube having a Shore A hardness of not more than 60, said odor barrier or pouch material having an arithmetic mean e roughness Ra not less than 0.1 µm. 5

6. A fecal catheter comprising an odor barrier al, the fecal catheter comprising: a silicone tube; at least one layer of nanocomposite coating on said tube; and at least one layer of a silane coupling agent; 10 said coated tube having an oxygen transmission rate of no more than 20,000 cc/m2/day and a e having an arithmetic mean surface roughness Ra not less than 0.1 µm.

7. The fecal catheter of claim 6, wherein the odor barrier material 15 comprises a zeolite.

8. The fecal catheter of claim 6 or 7, wherein the oxygen barrier transmission rate per ASTM D3985 is 1000 cc/m2/day or less at 23°C. 20

9. The fecal catheter of any one of claims 6 to 8, wherein said catheter does not crack upon flexing.

10. The fecal catheter of any one of claims 6 to 9, wherein said catheter is extruded and may be converted both by welding and adhesive bonding.

11. The fecal catheter of any one of claims 6 to 10, n said arithmetic mean surface roughness is on the inner surface of the fecal catheter.

12. An odor barrier material for a fecal catheter or ostomy pouch, the odor 30 barrier material comprising: an elastomer selected from a group including silicone, polyurethane, styrenic block copolymer, thermoplastic vulcanizate and polyolefin elastomer; an antiblocking agent, n the antiblocking agent is selected from 35 the group consisting of nic fillers, including silica, talc, clay, and mica, and any ation thereof, that imparts a rough surface to prevent blocking, wherein said surface has an arithmetic mean surface roughness Ra not less than 0.1 µm. 5

13. The odor barrier material of claim 12, wherein the surface roughness is not less than 1 µm.

14. The odor barrier al of claim 12 or 13, further comprising a zeolite. 10

15. The odor barrier material of any one of claims 12 to 14, wherein the inside surface of the fecal catheter or ostomy pouch has an arithmetic mean surface roughness Ra not less than 0.1 µm.