TECHNICAL FIELD

The present disclosure relates to medical devices which have a substrate including a hydrophilic coating thereon. More particularly, the present disclosure relates to medical devices for insertion into a body and, even more particularly, medical devices for insertion into lumens or passageways of the body, e.g., urinary catheters and endoscopes. The present disclosure also relates to methods of using and making such medical devices.

BACKGROUND

In the medical field, and in other fields as well, the surface of a device may be coated with a hydrophilic coating that becomes lubricious upon contact with water to ease insertion of the device into the body. Such lubricious hydrophilic coatings may be disposed on urinary catheters, vascular catheter, catheter guide wires, and other medical devices that are meant to be inserted into the body. The lubricious nature of such materials allows the insertion (and subsequent removal) of a catheter or other medical device to be accomplished with minimum resistance, thereby reducing discomfort and possible injury.

While the use of lubricious hydrophilic coatings on medical devices is becoming more common, it remains difficult to prepare a lubricious hydrophilic coating that securely attaches to the substrate surface. Secure attachment of the lubricious coating to the substrate surface is generally desirable and particularly useful in the medical field, where secure attachment of the coating is often an important requirement.

In many instances, securing the hydrophilic coating to a substrate surface includes the use of primer layer or tie layer that has good attachment to both the substrate surface and the hydrophilic layer. When a primer layer is employed, the primer layer is disposed or coated onto the surface of the medical device, after which the top hydrophilic coating is disposed on the primer layer. The primer layer attaches to both the substrate surface and the hydrophilic layer to securely attach the hydrophilic layer to the substrate. While the use of a primer layer may provide sufficient attachment of the hydrophilic coating, such use may be undesirable because it requires the use of an extra coating layer and additional steps and time in the preparation and manufacture of the medical device.

Therefore, there is a need for medical devices that have a hydrophilic coating securely anchored directly to the surface of the substrate of the medical device without the use of a primer layer.

BRIEF SUMMARY

There are several aspects of the present subject matter which may be embodied separately or together in the devices and systems described and claimed below. These aspects may be employed alone or in combination with other aspects of the subject matter described herein, and the description of these aspects together is not intended to preclude the use of these aspects separately or the claiming of such aspects separately or in different combinations as set forth in the claims appended hereto.

In one aspect, a urinary catheter includes a catheter tube wherein at least a portion of the catheter tube is made from a blend of an ethylene and/or propylene based polymer and a water-swellable polymer. The catheter also includes a hydrophilic coating disposed on at least a portion of an outer surface of the catheter tube. The ethylene and/or propylene based polymer may have a density less than or equal than 0.95 g/cm3. Additionally, the outer surface of the catheter tube may have a surface energy of at least about 30 mN/m.

In another aspect, a urinary catheter includes a catheter tube wherein at least a portion of the catheter tube is made from a blend of an ethylene and/or propylene based polymer and a water-swellable material.

In yet another aspect, a method of making a urinary catheter that includes the step of blending an ethylene and/or propylene based polymer with a water swellable material to form a blend. The blend is formed into a urinary catheter tube having an outer surface and a hydrophilic coating is disposed on the outer surface.

