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

Why you won't get your coated medical device to market in 6 months

Posted by Josh Simon on Wed, Jun 13, 2012 @ 04:23

If anyone has ever been starry-eyed, it's me.  "I am going to get my PhD in only three years!"  "I will have all this extra money with this new job!"  "I will probably retire at 55!"  Of course, at that point reality rudely awakens me.  Shucks.

I am not old yet, but I am old enough to try and catch myself now when I start convincing myself about things like this.  I smile it away and shake my head.  Back to reality.

So it goes for other people, too.  In my job, the one I hear most often is, "I will get my medical device with a hydrophilic coating through clinical trials and to market in six months!" 

Well, if today is the first day you have talked to me about a hydrophilic coating on your medical device, no you won't.  Sorry!  Maybe six months from now, if all goes well, you can say that, but certainly not in our first conversation.

I have written similar articles on this blog before, and I still need to get the word out:  Hydrophilic coatings are not trivial.  They are sophisticated and advanced additions that add real value to some medical devices, and they require an entire level of attention to detail, all their own.

If you are coming to me with a six-month deadline to market, you are TOO LATE.  My next line to you will be, "Can you extend your timeline?"  By the way, this does not only occur with inexperienced startups developing their first medical devices.  This sometimes happens with veteran engineers too.

So, why then?

It breaks down into a few reasons:

  • Coating equipment always needs customization
  • The coatings themselves often need customization
  • Ordering machinery has a lead time
  • IQ, OQ, PQ take time
  • Devices with coatings must go through Verification and Validation, as per Design Controls, at least in the US
  • Clinical trials, at least in the US, require an IDE if they are significant risk, which takes time to get
  • FDA Clearance or Approval always takes at least 60 days

So, just do the math.  A proper aging study on a hydrophilic coating takes 4 months if you want a three-year shelf life.  You can do other things in parallel with that, certainly.  The lead time on the equipment alone can be four to six months, so even if you get the equipment in just three months, you still need to do IQ, OQ, PQ on it.  Also, this is if the type of equipment is exactly known from day one.  That never happens because every catheter shaft has holes at different spots, or different diameters, or shapes, etc, or maybe it is not even a catheter so it needs a different kind of machine invented entirely.  However, will that be possible if you still do not have your coating formulation nailed down yet?  If you are assuming that you will get a perfect coating on your first sample run and simply scale things up from there, you are mistaken most times.

These things take time.  Believe me, I would also love it if you could get to market in six months.  It makes the money come in a lot faster.  Reality is different.  Usually all of these things take the better part of a year, if everything goes smoothly, and in many cases they take the better part of two or three years.

I do not want to discourage anyone from trying a coating.  It can add real value to your device, and some devices may not be able to exist without one.  I do want to educate people about how long this stuff can take, however.

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

MDM East Wrapup - Hydrophilic Coatings

Posted by Josh Simon on Thu, May 24, 2012 @ 03:23

This year is the first year that MDM East is in Philadelphia, which is essentially my own backyard.  I had a chance to spend two days at the show (and it is not over yet by the time of this writing.)

Many of the regular crowd members of the hydrophilic coating industry were present at the show.  I saw booths for Advansource, Hydromer, BioInteractions, DSM, Surmodics, Harland, and that company that owns Medi-Solv.  Absent were booths for AST, Coatings2Go, and my own employer, Biocoat. (Forgive me, please, if I forgot anyone.)

Not having to man a booth gave me a lot of time to wander and meet with people.  Interestingly, I had the impression from just about all of the hydrophilic coating companies that the show was "meh".  (That would be an onomontopeia for the sound you make when you are generally NOT impressed.)

Really that all boils down to number of leads obtained at the show.  The comment I heard most often, multiple times, was that the show was great for catching up with current customers and seeing people that you already know, but not so great for meeting new faces.  Comments went on to suggest that the MDM/BIOMED show circuit is saturated, i.e. there are too many of them in too many places that are not so far away from each other (like Chicago vs. Minneapolis, anyone?).  Coating companies are hungry for new blood, and frankly a little tired of fighting over the same customers time after time.

 

MDM East

Tags: medical device coating, Hydrophilic Coating, coatings companies, coatings vendor, medical device coatings, hydrophilic coatings, coatings customers, coatings manufacturer, MDM East

Hydrophilic Coatings Particulate

Posted by Josh Simon on Fri, May 11, 2012 @ 02:54

As promised to one reader, I am putting a little bit more information here on particulates and particulate testing with regards to hydrophilic coatings.

The first thing I want to do is point you to some great information on general theory and the regulatory status of particulates for medical devices.  There is an excellent article by Susan Reynolds and Ryan Lunceford on the basics of particulate testing.  It talks about the prevalent use of USP 788, as I have done in my previous article on medical device particulates here, including some specifics on the differences between laser counting versus microscopic counting of particles.

The article is a few years old, and at that time, the AAMI was not yet finished writing its report on setting medical device particulate limits.  However, now that report is out, and you can find it here.  Personally, I found it a little vague.  It does not give any sort of concrete limits to follow, and is not any sort of draft guidance.  It is good for figuring out how to think about this when going about your own particulate tests, however.

One item touched on by both the AAMI report and the article is composition.  Specifically for hydrophilic coatings and/or lubricious coatings, these particles have characteristic identities.  Like anything else, a major consituent of particulate could be clean room dust, which originates from human skin or clothing, or other particles tracked in from the outside.  However, after abrasion, it can also be due to coating wear particulate.  In fact, one method of testing durability for a hydrophilic coating is to run it through a tortuous path test and then measure the amount of particulate in the path after multiple cycles.  For increasing number of cycles, you can track the increase in particle count.

Again, this is just an idea and not a standard.  There are no suggested limits for a test like this right now.  Everything in this field is at this point "unregulated", and we are all concerned about what the FDA will eventually do to throw a wrench in the innovation in the name of hypersensitivity. 

 

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Tags: lubricious coating, Hydrophilic Coating, medical device coatings, hydrophilic coatings, lubricious coatings, particulate testing

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

5 Critical Questions to Ask About Pinch Testing Data

Posted by Josh Simon on Thu, Jan 26, 2012 @ 04:54

Pinch testing data can be used to make or break a lubricious hydrophilic coating.  It can also be used to lie.  When you see any graph depicting lubricity and durability for a coating, it is time to stop and take a breath before absorbing the data.  Ask yourself about the nature of the test used to get the information. 

pinch tester

Some hydrophilic coatings can be painted as amazingly slick and durable, but when put to a rigorous test, not so much.  Others shine and duke it out among the top.  I will soon be publishing a white paper demonstrating how differences in testing methods can make big variations in friction outcomes.  Below is a preview table of the 5 questions to ask yourself whenever you view friction data for a lubricious coating.

Question

Issue

For what Load does the current data display?

Tests using lower loads can give the appearance of a durable coating.

What is the pinch pad material used in the test?

Soft pinch pad materials are easier on the coating, and can portray favorable results.

What is the substrate material used in the test?

Soft substrates are easier on the coating, and can portray favorable results.

Was the test conducted under saline, pure water, or dry?

For medical devices, performance in saline is most clinically relevant, but dry or pure water performance can be used to artificially portray a coating in a positive or negative light, compared to actual in vivo performance.

How many cycles are displayed in the test data?

Low cycle numbers may not show a difference between two coatings, or be used to sidestep durability issues.

Tags: lubricious coating, medical device coating, pinch tester, medical device coatings, lubricious coatings, pinch testing, 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

Lubricious Coating: Regulatory & Economic Landscape

Posted by Josh Simon on Thu, Oct 06, 2011 @ 03:54

The folks at MDDI have posted an article contributed by me on the Regulatory and Economic Landscape for Hydrophilic Coatings, in my opinion. Normally I post these musings here, but MDDI wanted to pick up the article from me, so enjoy!

If you are looking for coatings, and want to talk personally with the big players in that arena, do not hesitate to attend the MDM Minneapolis trade show coming up.

 

MDM Minn 4c resized 600

Tags: medical device coating, coatings companies, coatings vendor, coating company, business of hydrophilic coating, coating manufacturer, medical device development, medical device coatings, lubricious coatings, coatings customers, coatings manufacturer, FDA regulation of coatings, coatings supplier

Leachables vs. Extractables - Hydrophilic Coating Considerations

Posted by Josh Simon on Mon, Sep 26, 2011 @ 10:00

The Qmed blog has an insightful article on differentiating between leachables and extractables in medical devices.  Though the article does not specifically mention lubricious hydrophilic coatings, it is still an important consideration. 

Something to know:  All hydrophilic coatings contain multiple ingredients, some of which are not completely bound within.  Even crosslinked coatings that purport to be chemically resistant still contain unreacted products from whatever reactions are used in the crosslinking.  The article at Qmed makes us aware that these sorts of leftovers can either leach out or be extracted out, and there is a difference.

The author notes that leaching occurs under "normal" conditions of use, i.e. what will come out of your coating when you place it in the body at 37C for some length of time?  Extraction is what happens during exaggerated conditions, i.e. what will come out of the coating at 50C in an acidic water bath, or an oil bath?

Extractables can give clues to what the leachables might be.  They can also tell you how stable your material is, chemically.  The presence of an extractable is not necessarily a show-stopper.  Unwanted leachables might be harder to explain, however.  Either way, both of these things will make up part of the larger picture of biocompatibility for your material.

 

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Tags: lubricious coating, medical device coating, Hydrophilic Coating, biomaterials, medical device development, medical device coatings, hydrophilic coatings, lubricious coatings, FDA regulation of coatings, extractables, leachables

Hydrophilic Coatings Webinar Available Online

Posted by Josh Simon on Fri, Sep 23, 2011 @ 02:11

med medicalcoatings bannerark resized 600

An archive of the webinar we recently announced on hydrophilic and hydrophobic coatings is now available to everyone for download.  Please stop by and grab the file and listen to it.

Click here to download the hydrophilic coatings webinar.

The webinar was sponsored by Biocoat and Specialty Coating Systems. Half of the presentation by Josh Simon is actually about hydrophilic coatings and the second half by Lonny Wolgemuth talks about hydrophobic coatings. Remember, hydrophilic means "water loving". Hydrophobic means "water fearing". The webinar sets the record straight on which is which and why you would want to use some in specific applications.

For both coatings, lubricity is discussed, i.e. how slippery they are respectively, as well as some basic mechanical properties and medical device applications. 

All in all, I am told this is a pretty good overview of coatings, and it is a nice place to start if you are just beginning your research on this area for possible future products or medical devices. 

 

Tags: advanced coating, lubricious coating, medical device coating, Hydrophilic Coating, hydrophobic coating, Biocoat, parylene, coatings companies, coating company, business of hydrophilic coating, coating manufacturer, biomaterials, basecoat, durability, durability testing, coating cost, coating costs, Specialty Coatings Systems, medical device coatings, hydrophilic coatings, lubricious coatings, coatings customers, coatings manufacturer, coatings supplier