Coating for use with medical devices and method of making same

Abstract

The inventive coating may be employed to deliver a pharmaceutical agent to a selected body area that is involved within the insertion or application of a medical device. Such medical devices may include silicone based urinary catheters and other medical implants as well as other silicone based devices having deformable portions which could benefit from the release of a pharmaceutical agent from its surface. The coating allows the introduction of the pharmacological additive having a release rate that is within acceptable pharmacokinetic criteria. The release rate is adjusted by utilizing different salt forms of the additive and adjusting the concentration of urethane and RTV silicone. The coating incorporates additive compounds such as anti-microbial, anti-fungals and other organic compounds. Methods are also provided for the manufacture of the subject coating and for the application of the same to surfaces of medical devices.

Description

BACKGROUND [0001] 1. Technical Field [0002] The present disclosure relates to a coating for silicone based medical devices, and more particularly, to a coating which allows a pharmaceutical agent to be released from an internal and / or external surface of such medical devices. [0003] 2. Background of the Related Art [0004] Various medical devices that are inserted into body cavities of humans and animals can unfortunately introduce bacterial, viral and fungal infections into these body cavities. Numerous coatings are available for medical devices that employ polyurethane or urethane pre-polymers to act as lubricants, drug delivery systems and the like. Known coatings applied to surfaces of medical devices include coatings of polyvinylpyrrolidone, polyurethane, acrylic polyester, vinyl resin, fluorocarbons, silicone rubber, and combinations of these substances. For example, U.S. Pat. Nos. 4,100,309 and 4,119,094 to Micklus et al., relate to a hydrophilic coating of polyvinylpyrrolidon...

AI Technical Summary

Benefits of technology

[0009] As is described in greater detail below, the present disclosure provides a coating composition including a combination of RTV silicone and urethane. The combination of RTV silicone and urethane produces an inventive coating that facilitates drug delivery and enhances adherence to a flexible silicone medical device. The inventive coating provides adherence over highly expanded surfaces such as, for example, catheter balloons, etc.

Problems solved by technology

Various medical devices that are inserted into body cavities of humans and animals can unfortunately introduce bacterial, viral and fungal infections into these body cavities.

While the above coatings are appropriate for application to urethane, polyvinylchloride (PVC), steel or polyesters, these systems offer poor adherence to silicone medical devices unless the silicone surface is subjected to corona or plasma treatment.

The need to pre-treat these silicone based medical devices limits coatings to surfaces that are pre-treated by the above methods, resulting in additional manufacturing process steps, additional costs and variability of the medical device.

Additionally, the above methods have not been adequate as performance of the coatings has been unsatisfactory over flexible or expandable segments of medical devices such as catheter balloons.

However, these methods do not overcome the inherently poor drug delivery properties of silicone.

These problematic silicone drug delivery properties include poor diffusion of the drug in a hydrophobic environment and surfaces that resist subsequent application of a hydrophilic bolus coating or lubricious coating.