For medical device companies who are developing intravenous products to support life-saving procedures, the selection of a hydrophilic coating plays an integral part in the performance of the device. Today’s hydrophilic coatings must exhibit three criteria to qualify as acceptable for use: lubricity, durability and low particulates to ensure that the device will meet the testing requirements from global regulatory agencies such as the FDA and EMA.
To apply a hydrophilic coating to a medical device, there are two primary methods used to dry and cure the coating: ultraviolet (UV) light and thermal heat. The selection of the curing methodology depends on several factors, including throughput, coating durability, space in the manufacturing location, curing equipment, market application and the substrate that the device is made of. This article will review the differences between UV and thermal heat cure coatings to support your decision making when selecting a hydrophilic coating.
Understanding a Hydrophilic Coating Application
The lubricous (slippery) nature of hydrophilic coatings make them ideal for medical devices. They allow the device to easily traverse the vasculature, avoiding possible puncture damage to vessel walls and eliminating abrasion between the device surface and the vessel walls. Hydrophilic coatings are most often used in, but not limited to, neurological, cardiovascular, peripheral vascular, urological and ophthalmic applications.
At Biocoat, we encourage our customers to analyze three major factors that measure the effectiveness of a coating. These factors are:
- Lubricity: The property that describes how slippery a surface is, i.e. the value of its coefficient of friction
- Durability: The strength of the coating that allows it to withstand the duration of procedure without degradation
- Particulates: The measure of the amount of foreign materials that are left in the body after the device is used in the procedure
As illustrated in Figure 1, the Biocoat R&D team purchased six different commercially available neurovascular microcatheters, two of which was coated with Biocoat’s HYDAK® Thermal Cure technology. The Biocoat team measured the number of particulates generated from each of the catheters to determine where HYDAK® performance stands in relation to industry competitors. Our testing proves that both HYDAK® UV and Thermal cure processes exhibit best-in-class lubricity and durability results. Catheters were cycled through an ASTM F2394 stent retention tortuous pathway.
Figure 2 demonstrates the lubricity and durability of our HYDAK® technology. The Biocoat R&D team purchased six different commercially available angioplasty catheters, one of which was coated with Biocoat’s Thermal Cure technology. We measured both the lubricity and durability of each of the microcatheters in an effort to determine where HYDAK® performances compares in relation to industry competitors. Our testing proves that HYDAK® exhibits “best-in-class” lubricity and durability results. The pinch test method used was silicone-pads and 470 g load with PBS at 37C.
Choosing Between Ultraviolet (UV) Light and Thermal Heat Cure Coatings
One of the important questions when choosing a hydrophilic coating is which type of curing will be employed for the application of the coating to the device. UV cure has traditionally been the popular choice, but thermal heat offers a different set of benefits. Biocoat is one of the only hydrophilic coating providers to offer industry-leading performance in both UV and thermal heat cure coatings. Biocoat’s HYDAK® coatings are applied via a bi-laminar platform using a base coat and a topcoat. The hydrophobic base coat is used to normalize the substrate material and to prepare the surface for the application of the hydrophilic topcoat. The base and topcoats are chemically bonded, which ensures an extremely durable coating adhesion and minimizes the release of particulates into the body.
Choosing between UV or thermal cure coatings depends on many factors, and your coating provider will be able to guide you to the benefits of each system. As one of the only providers that can offer industry-leading performance in both UV and thermal heat cure coatings, Biocoat is able to guide you to the best solution for your project’s needs.
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