Born slippy: Solving catheter problems with advanced chemistry
DiaNia Technologies is solving many catheter problems by harassing advanced polymer chemistry through materials science and engineering.
Demographics are playing a major part in the increased demand for today’s medical devices. This is due to an ageing population, rising health problems in younger generations eg obesity, diabetes, heart disease etc and an increase in home healthcare with the transition of acute illnesses into chronic diseases. Increasing healthcare costs are a constant topic on the agenda of all world leaders. Consequently, cost containment and austerity has forced many device manufacturers to rethink their long term product strategies through innovation.
One of the major issues encountered by users of catheter-based devices is the difficulty in delivering the device to the desired location in the anatomy, with a range of associated clinical risks from artery perforation and emboli formation to stroke and possible death. Extruded tubing is the core on which most catheters are built, with low friction being a key characteristic in reaching the correct location. However this low friction attribute within the system is the leading cause of problems like delamination, bond failures, leaks and detachment, buckling and crimping as illustrated in Figure 1. Current methods to reduce friction include Teflon/PTFE liners and/or hydrophilic coatings. These products are applied to the extrusion surface which adds numerous process steps and associated costs to the manufacturing cycle. Furthermore, the strength of the bond between all these components is dependent on the extrusions’ surface and is critical in facilitating function and safeguarding patient safety. Essentially the clinician’s demand for lubricity conflicts with the manufacturers need to secure device features such as soft tips, balloon bonds and stent retention.
Through the provision of in-built lubricous surfaces on the inner and outer diameter of an extrusion, ExtruLub technology not only has the ability to reduce both product and organisational costs but also facilitates reduced device profile enabling entry into smaller vessels.
X-ray photo spectroscopy (XPS), an analysis technique used to obtain chemical information about the surfaces of solid materials, was used to show that the properties at the surface of the ID and OD of an extrusion could be modified compared to a control group. The co-efficient of friction (COF) of pure Teflon liners is stated at close to 0.1[[1]], which became our first friction target. Subsequently, the COF was measured using the ASTM D1894 standard with a polymer on polymer test set up. The target COF was achieved with a hydrophilic ExtruLub surface in the PEBAX 7233 bulk resin, as shown in Figure 2.
A second feature of the ExtruLub technology is in the significant reduction in manufacturing cycle and complexity. Here it is compared in two sample devices, an intermittent catheter and a cardiology introducer. Higher value and margin opportunities are possible for the OEM at both the product and organisational level through reduction in process cycles, as is clearly evident from Figure 3.
In the case of an intermittent catheter, manufacturing costs of €1.00 are generally broken out into 40% materials, 40% Packaging and 20 % Overheads, with an average Actual Selling Price (ASP) estimated at €1.66[2]. Cost containment as set out in Figure 4 could realise an increase in gross margin of 13% per device. This increase multiplied by annual volumes, commonly for this type of device in the order of 100 mn units, could equate to savings in the region of tens of millions. In the second example, the containment of costs for an introducer is attainable through yield improvement, estimated at 17%, reduction in related costs and overheads at 50%, with further savings through shorter validation and production timelines as presented in Figure 4.
Hydrophilic coatings purport to enhance surface friction below values of 0.05, however, as the human body cannot differentiate friction below 0.05, our next friction target is to achieve 0.05, on which work is progressing well. The goal of DiaNia Technologies is to license ExtruLub technology to the OEM, enabling them to maintain control over their product lifecycle. So far innovation in catheters has relied mainly on novelty in engineering with surface modification achieved through coatings and polymer liners. DiaNia Technologies is solving many catheter problems by harassing advanced polymer chemistry through materials science and engineering. This type of solution is the key to advancing the next generation of medical devices globally, reducing clinical risk and facilitating new therapies whilst increasing the capability of current diagnostic and therapeutic treatments.
[1] http://www.microlumen.com/medical-tubing/ptfe-composite
[2] Bermingham, S. L., Hodgkinson, S., Wright, S., Hayter, E., Spinks, J., & Pellowe, C. (2013) “Intermittent self catheterisation with hydrophilic, gel reservoir, and non-coated catheters: a systematic review and cost effectiveness analysis.”British Medical Journal, 346.