INTERMITTENT CATHETERS

Abstract

The invention provides an intermittent catheter comprising a hollow polymeric tubular body comprising a base polymer and a layer comprising a lubricious additive on or comprising a surface of the body, wherein the lubricious additive comprises an amphiphilic molecule.

Claims

1. An intermittent catheter comprising a hollow polymeric tubular body comprising a base polymer and a layer comprising a lubricious additive on or comprising a surface of the body, wherein the lubricious additive comprises an amphiphilic molecule.

2. An intermittent catheter as claimed in claim 1, wherein the surface comprises an outer surface of the body.

3. An intermittent catheter as claimed in claim 2, wherein the layer comprising a lubricious additive is on or comprises at least 75% of the outer surface area of the body.

4. An intermittent catheter as claimed in claim 1, wherein at least 75% of the layer comprising a lubricious additive is the lubricious additive.

5. An intermittent catheter as claimed in claim 1, wherein the layer comprising a lubricious additive comprises an additive concentration of greater than 5% by weight of the combination of base polymer and layer comprising a lubricious additive.

6. An intermittent catheter as claimed in claim 1, wherein the layer comprising a lubricious additive comprises a thickness of between 50 and 300 μm.

7. An intermittent catheter as claimed in claim 1, wherein the body comprises a further lubricious additive.

8. An intermittent catheter as claimed in claim 7, wherein the further lubricious additive comprises the same lubricious additive as the layer comprising a lubricious additive.

9. An intermittent catheter as claimed in claim 1, wherein the layer comprising a lubricious additive is cross-linked.

10. An intermittent catheter as claimed in claim 1, wherein the amphiphilic additive is an amphiphilic A-B block copolymer comprising a hydrophobic hydrocarbon A-block and a hydrophilic B-block.

11. An intermittent catheter as claimed in claim 10, wherein the amphiphilic additive is an A-B block copolymer comprising an A-block comprising a hydrocarbon chain block of the formula CH.sub.3CH.sub.2(CH.sub.2CH.sub.2).sub.a where “a” is 5-25 and a hydrophilic B-block.

12. An intermittent catheter as claimed in claim 10, wherein the B-block is a hydrophilic oligomer comprising between 2 and 10 monomer units derived from one or more monomers selected from the group consisting of: alkylene oxides, alkylene glycols, epihalohydrins, unsaturated carboxylic acids, alkylene imines, lactones, vinyl alcohol, and vinyl alkanoates.

13. (canceled)

14. (canceled)

15. A method of manufacturing an intermittent catheter, the method comprising the step of extruding a base polymer and a lubricious additive to form a hollow polymeric tubular catheter body comprising the base polymer, and a layer comprising a lubricious additive on or comprising a surface of the catheter body.

16. A method as claimed in claim 15, wherein the method comprises co-extruding the base polymer and the layer comprising a lubricious additive simultaneously.

17. A method as claimed in claim 15, wherein the method comprises extrusion coating the lubricious additive on the surface of the catheter body.

18. A method as claimed in claim 15, wherein the method further comprises the step of cross-linking the layer comprising an additive.

19. A method as claimed in claim 15, wherein the layer comprising an additive comprises a hydrophilic or amphiphilic molecule.

20. A method as claimed in claim 19, wherein the amphiphilic additive is an amphiphilic A-B block copolymer comprising a hydrophobic hydrocarbon A-block and a hydrophilic B-block.

21. A method as claimed in claim 20, wherein the amphiphilic additive is an A-B block copolymer comprising an A-block comprising a hydrocarbon chain block of the formula CH.sub.3CH.sub.2(CH.sub.2CH.sub.2).sub.a where “a” is 5-25, and a hydrophilic B-block.

22. A method as claimed in claim 20, wherein the B-block is a hydrophilic oligomer comprising between 2 and 10 monomer units derived from one or more monomers selected from the group consisting of: alkylene oxides, alkylene glycols, epihalohydrins, unsaturated carboxylic acids, alkylene imines, lactones, vinyl alcohol, and vinyl alkanoates.

23-26. (Canceled)

Description

DETAILED DESCRIPTION OF THE INVENTION

[0174] In order that the invention may be more clearly understood embodiments thereof will now be described, by way of example only:

Example 1

[0175] A first embodiment of an intermittent catheter of the invention comprises an intermittent catheter comprising a hollow polymeric tubular body comprising a base polymer formed of polyethylene and further comprising an amphiphilic additive of the formula CH.sub.3CH.sub.2(CH.sub.2CH.sub.2).sub.20(OCH.sub.2CH.sub.2).sub.8OH present as a layer comprising the complete outer surface of the body of the catheter. The layer comprising an additive is physically entangled and melded with the body, holding it in place. The amphiphilic additive comprises a hydrophilic block which seeks away from the body and towards the external environment due to its incompatibility with the base polymer, the outer surface becoming lubricious as a result. The lipophilic and hydrophobic block of the amphiphilic additive further ensures that the hydrophilic block is secured to the base material.

[0176] The intermittent catheter may be prepared as described in US patents U.S. Pat. Nos. 10,058,638 B2 and 9,186,438 B2, but without adding the additive to the base polymer mixture and with an added co-melt extrusion step. This step involves melting both the base polymer mixture and lubricious additive and delivering a steady volumetric throughput of both the mixture and additive to a single extrusion head under pressure, which allows for co-extrusion of the layer comprising a lubricious additive and the base polymer simultaneously. The high temperature and pressure employed in the co-extrusion step allows for entanglements to form between the base polymer polyethylene chains and the additive molecules. After co-extrusion, the catheter is cooled to allow the catheter body to solidify.

[0177] The layer comprising an additive comprises a thickness of 70 μm and an additive concentration of 3% by weight of the combination of the base polymer and the layer comprising an additive.

[0178] The intermittent catheter is used in the conventional manner.

[0179] The layer comprising an amphiphilic additive on the outer surface of the catheter body confers higher lubricity to the outer surface of the intermittent catheter than conventional intermittent catheters of the prior art, making it both easier to insert and remove, even with the additive being present in a low concentration. Despite the additive being entirely on the outer surface of the catheter, the melds and entanglements between the base polymer and the layer comprising an additive mean that migration of the additive away from the catheter surface is comparable to or even lower than conventional intermittent catheters of the prior art.

Example 2

[0180] A second embodiment of an intermittent catheter of the invention comprises an intermittent catheter comprising a hollow polymeric tubular body comprising a base polymer formed of thermoplastic polypropylene and further comprising an amphiphilic additive of the formula CH.sub.3CH.sub.2(CH.sub.2CH.sub.2).sub.15(OCH.sub.2CH.sub.2).sub.5OH present in the body and as a layer comprising the lubricious additive on the complete outer surface of the body of the catheter. The amphiphilic additive comprises a hydrophilic block which seeks away from the body and towards the external environment due to its incompatibility with the base polymer, the outer surface becoming lubricious as a result. The lipophilic and hydrophobic block of the amphiphilic additive ensures that the hydrophilic block is secured to the base material.

[0181] The intermittent catheter may be prepared as described in US patents U.S. Pat. Nos. 10,058,638 B2 and 9,186,438 B2, but with the added step of extrusion coating the layer comprising a lubricious additive on the outer surface of the catheter body after forming the body. This step can be performed using a blown or cast film process to coat the layer comprising an additive as a molten web of synthetic resin onto the outer surface of the intermittent catheter body after its formation. The process involves extruding the molten layer comprising an additive from a slot die directly onto a tacky catheter body that is moved beneath the die to form the layer on the outer surface of the catheter. The catheter is then cooled to bring the molten film of additive back into a solid/gel state and to completely solidify the tacky catheter body.

[0182] The layer comprising an additive comprises a thickness of 100 μm and an additive concentration of 6% by weight of the combination of the base polymer and the layer comprising an additive.

[0183] The intermittent catheter is used in the conventional manner.

[0184] The layer comprising an amphiphilic additive confers high lubricity to the outer surface of the intermittent catheter and the further additive in the body also seeks towards the outer surface of the catheter and enhances the surface lubricity. Accordingly, the catheter comprises much higher lubricity on its outer surface than conventional intermittent catheters of the prior art, making it both easier to insert and remove.

Example 3

[0185] A third embodiment of an intermittent catheter of the invention comprises an intermittent catheter comprising a hollow polymeric tubular body comprising a base polymer formed of thermoplastic polyethylene and further comprising an amphiphilic additive of the formula CH.sub.3CH.sub.2(CH.sub.2CH.sub.2).sub.10(OCH.sub.2CH.sub.2).sub.4OH present as a layer comprising the complete outer surface of the body of the catheter. The amphiphilic additive confers lubricity to the outer surface. The lipophilic and hydrophobic block of the amphiphilic additive helps secure it to the base material and the layer comprising an additive is also physically entangled with the body.

[0186] The layer comprising an additive is also independently cross-linked through non-covalent bonds formed between the poly(ethylene oxide) groups and a urea complexing agent.

[0187] The non-cross-linked intermittent catheter may be prepared as described in Example 1. The layer comprising an amphiphilic additive may be independently cross-linked by packaging the non-cross-linked intermittent catheter submerged in a urea cross-linking inducing solution.

[0188] Having the additive present as a layer comprising the outer surface of the catheter body has the advantage of limiting the depth of penetration required by the cross-linking inducing medium to initiate the cross-linking.

[0189] The layer comprising an additive comprises a thickness of 70 μm and an additive concentration of 3% by weight of the combination of the base polymer and the layer comprising an additive.

[0190] The intermittent catheter is used in the conventional manner.

[0191] The layer comprising an amphiphilic additive on the outer surface of the catheter body confers high lubricity to the outer surface of the intermittent catheter even with a low additive concentration, as in Example 1.

[0192] The additive cross-links increase the difficulty for the additive to migrate, particularly out of the intermittent catheter. Cross-linking is believed to reduce the mobility of the polymer matrix, which in turn restricts the migration of the additive out of the catheter. This allows the intermittent catheter to retain its lubricity for longer even when packaged in water or aqueous solutions.

[0193] The intermittent catheter of Example 3 conferred reduced migration of the amphiphilic additive from the surface of the catheter during both storage/transport and through use of the catheter. It also provided increased resistance to abrasion of the additive from the surface of the catheter on contact with external bodies.

Example 4

[0194] A fourth embodiment of an intermittent catheter of the invention comprises the intermittent catheter of Example 1 packaged in a packaging container with a wetting agent.

[0195] The intermittent catheter is produced as detailed in Example 1. After formation of the coated catheter, it was packaged in a sterile sachet comprising a saline solution wetting agent. The intermittent catheter is fully submerged in the saline solution, which allows for activation of the lubricious outer surface of the catheter due to hydrophilic-hydrophilic interactions between the hydrophilic block of the amphiphilic additive and the hydrophilic wetting agent. The hydrophilic-hydrophilic interactions ensure that the hydrophilic blocks of the additive molecules seek away from the body and towards the external environment, generating a highly lubricious outer surface.

[0196] Due to the additive being entirely on the outer surface of the catheter, the wetting agent is able to generate lubricious outer surface instantaneously, and which will be active as soon as a health care professional or user removes the catheter.

[0197] The above embodiments are described by way of example only. Many variations are possible without departing from the scope of the invention as defined in the appended claims.