Lubricious Coatings in spec, on time, and on budget

Posted by Josh Simon on Mon, Aug 13, 2012 @ 12:02

Ultimately on this blog, I try to keep the marketing of my own products to a minimum because what I am trying to do here is provide an educational resource.  The title is deceptive, therefore, because I am actually thinking broadly and more literally about how any lubricious coating can be applied in spec, on time, and on budget.  I do this because I was recently presented with a marketing piece from a medical device development company that broke their services down into precisely those three categories.

So, what is involved with getting a hydrophilic coating onto a commercial device in spec, on time, and on budget, and how much of that is dependent on the vendor versus just plain old reality?

Let me focus on specs in this article.  Maybe later I will cover the others.

A couple of years ago, I posted a checklist for hydrophilic coatings.  That post explained many of the questions a potential client should answer before contacting a vendor.  Like the coatings white paper I wrote on the same basic subject, it explains that you need to at least know what the device will be used for, i.e. what industry, what procedure, as well as what the materials used in the device are, among other things.

Once those things are known, there is another layer below that.  For example, lubricity is a broad term to mean slipperiness, but just how slippery should the medical device surface be?  What coefficient of friction do you want?  0.1?  0.01?  Teflon is a great hydrophobic coating that can go as low as 0.1, but true hydrophilic coatings are needed to get to 0.01. 

After understanding the friction (or lack thereof) at the surface, what sort of use will the device experience?  Is it going to be quickly inserted in vivo and then removed after a few seconds, or is it going to abrade against the inner lumen of a blood vessel, or maybe even another hard plastic catheter?

Being able to tell your coating vendor what you want is important, and that is independent of the coating vendor.  In some ways, most hydrophilic coatings on the market are the same, but they do differ in other important ways as far as processing, composition, and business models.  They also can influence the other two pieces of this puzzle:  time and budget.

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Tags: medical device, advanced coating, lubricious coating, medical device coating, Hydrophilic Coating, medical device development, medical device coatings, hydrophilic coatings, lubricious coatings

Medical Device Industry - An Informal Survey

Posted by Josh Simon on Tue, Jul 31, 2012 @ 09:04

Over at the Medical Design Perpectives blog, I have a guest article there about a trip I took to visit almost 50 medical device companies over the last three months.  The trip was ultimately for the purpose of selling our hydrophilic coatings, but what wound up happening is I got a great set of answers to some questions about where the medical device industry is heading.

 

Medical device companies are heading outside the US, to put it simply.

Tags: medical device, Regulatory, medical device development

Verification of Lubricious Coatings on Medical Devices

Posted by Josh Simon on Wed, Mar 21, 2012 @ 10:43

I have hinted much on this blog about ways to go about verifying hydrophilic coatings on medical devices.  When I speak of "verification", I am talking about the first "V" in "V&V", i.e. the Verification step in Design Controls that may or may not precede a Validation step, depending on the device.  As you may quickly realize, speaking about specific verification steps for any device is a huge task, because verification is nothing more and nothing less than confirming that design inputs = design outputs.  Does your device prototype meet specification?  Since every device in the world has different specifications, it is impossible to come up with ways that apply to all devices.

However, for lubricious coatings there are some general themes that pop up which are widely applicable, even though specific verification tests may vary per device. 

 

Adhesion

In all but rare cases, if you are coating a device, you want the coating to stick, at least for a while.  You may not care if the coating ultimately resorbs, or you might care.  However, in most cases, you would not be satisfied if the coating flaked off and left material behind in the body.  Thus, some sort of adhesion test is necessary.  For flat surfaces, ASTM D3359-78 may be appropriate.  This is known as the "tape test". Modifications to this test would be necessary for curved or irregular surfaces.  Adhesion can also be tested with a pinch test indirectly.

Lubricity

If using a lubricious coating, you obviously want it to be slipperier than a device without the coating.  Thus, your verification process will require some testing of lubricity against a control, and/or to your spec.  Pinch testing is also an option for this, and you can click on the button below to get an article that goes into details on that.  There are also other tests you can rig up, such as an anatomical model for sliding your coated article through it and measuring force or ease of insertion/withdrawal.  The pinch test paper mentions four major kinds of lubricity tests. However, the limitation of most lubricity tests is that they do no correlate to clinical use.   Despite this limitation, they can still be a good basis for making an engineering decision.

 

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Sterilization

Most sterilization testing involves bioburden analysis, i.e. making sure that you get a 4-log kill (or whatever your spec states).  The other thing to think about is how the sterilization method will affect your coating, so you will need to do coating performance tests after sterilization, as well as before (if that is still relevant to you).  Performance testing can be the same type of tests mentioned above for Adhesion and Lubricity.

Aging

Once you have a favored set of tests and output variables, such as lubricity via pinch testing, or adhesion via tape test, you can keep using those tests over and over for environmental effects, such as Aging.  Does your coating remain lubricious after aging?  This can be accelerated aging, but make sure the conditions of acceleration do not adversely affect the coating.  For example, if your coating is sensitive to water vapor, do not run an aging study at 100% Relative Humidity, because it will not correlate with real time.

Transportation and Handling

How will people treat your lubricious coating on the road, in the doc's office, during shipping, at the patients' houses?  The first step is to do a shipping study.  Send the coated article somewhere and test its performance.  Make sure it stands up.  From there, you can gradually get more nasty by subjecting it to harsher environments, mimicing the trunk of a sales rep's car on a hot day in Puerto Rico, for instance.  Again, you will be using your preferred performance output variables.

Differences in testing will be dictated by what your device actually is.  Is it an IOL Cartridge?  Is it a Jamshidi needle?  Is it a coronary guidewire? 

Also, this list is by far not exhaustive.  I have not even mentioned things like biocompatibility and particulate testing.  I wonder if I should make several parts to this post?

 

Tags: medical device, medical device coating, lubricity, medical device development, medical device coatings, hydrophilic coatings, lubricious coatings, lubricity testing

Hydrophilic Coatings Market Misinformation - Part 2

Posted by Josh Simon on Wed, Jan 11, 2012 @ 10:06

Last week I discussed why some of the estimates that the professional market research organizations make on the size of the medical device coatings market are a bit off.  I did not want to throw everything at you at once, so this week I will continue with the topic.

There is one other area where errors are made in estimating market size.  Let us take the example of a company that has developed its own antimicrobial coating for its own use.  In fact, currently there are several such examples of companies that do this:  Edwards Lifesciences, Cook Medical, B. Braun, and Medtronic. 

These companies employ their antimicrobial coatings on their own devices and gain revenue from sales.  For any one of the examples above, the sales on a given antimicrobial device are in the millions.  The mistake made by the market researchers is adding the revenue of these devices into their market size calculation.  If Cook Medical's minocycline/rifampin line of catheters sells $100 million per year (a number which I just made up off the top of my head), the market reports will add that $100 million to the market size.

This is incorrect.  When a company produces its own antimicrobial coating only for its own devices, it is not licensing out that coating or supplying it to others in any way.  However, what if they were?  Or, what if instead of using their own coating, they licensed an antimicrobial coating from a coating vendor and paid a royalty on it?  The revenue from the licensing and royalties to the coating vendor would be the number added into Market Size for medical device coatings. 

So, my proposal is that instead of simply adding the $100 million to the market size, what the researchers should do is pretend that those coatings were licensed from a coating company and then calculate the revenue gained by the theoretical coating vendor for those coatings.  This isolates the coatings revenue from the device revenue.

Afterall, we are looking at a coatings market, not a device market, so the revenues should be separated out.  Reports that talk about coated device markets might help coated device vendors, but they require all sorts of mental rejiggering to become useful for coating companies.

When you sell house paint, do you look at the selling price of all the houses you are going to paint, or do you look at how many gallons of house paint you are going to use to paint them?

 

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Tags: medical device, medical device coating, Hydrophilic Coating, medical device coatings, hydrophilic coatings, antimicrobial coating, hydrophilic coating market