Josh Simon

Recent Posts

Biocoat Releases Three New Hydrophilic Coatings

Posted by Josh Simon on Mon, Apr 30, 2012 @ 03:50


Biocoat, Inc., maker of lubricious HYDAK® hydrophilic coatings introduced three new hydrophilic coatings for medical devices to its classic lineup. "HydroSleek2", the new successor to the original HydroSleek lubricious coating, with improved processing and biocompatibility. "The HydroSleek Kit" is another variation on the HydroSleek coating, which allows the product to be stored and transported under a wider array of conditions. Third, the "Hydak® T-040 Kit" is a remake of another classic, Hydak® L-110, also allowing for wider availability to Asian and European markets.

All of these coatings are based on high molecular weight Hyaluronic Acid (HA). This technology has applications among a range of fields including ophthalmology, urology, cardiology, endoscopy, and neurovascular. HydroSleek coatings have overcome the trade off between lubricity and durability seen in cross-linked coatings. Additionally, HydroSleek involves a heat-cure process so both ID and OD may be coated without the concerns surrounding UV curing.

These new products will act as Biocoat's front line solution to medical device firms seeking to reduce surface friction for their devices. Each of these new products possesses the same beneficial characteristics of the family of HYDAK® coatings, plus advancements device manufacturers have requested.

For further comments or questions, email Dr. Josh Simon, Senior Product Manager at jsimon at biocoat dot com.


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Tags: lubricious coating, medical device coating, Hydrophilic Coating, Biocoat, hydrophilic coatings, lubricious coatings

Practical Challenges for Medical Device Coatings

Posted by Josh Simon on Fri, Apr 20, 2012 @ 04:41

I still plan to talk a little more about particulates as promised, but I wanted to take a break and point out an article I have out in Medical Design Technology.

The title is Practical Challenges for Medical Device Coatings, and as you may guess, it spells out some things to think about when looking at coating data. This is not just for hydrophilic coatings, but for many other kinds as well.

The full issue of Medical Design Technology is found here.  To get to my article, turn to page 24, or click on the link to the article in the Table of Contents.

I dislike these digital edition magazines becasue they hide all their content behind a single URL and that does not let you link directly to an article, nor does it let anyone get search engine credit for it.

MD1203cover resized 600

Tags: lubricious coating, medical device coating, Hydrophilic Coating, antimicrobial coating, anti-fouling coating

Lubricious Coating Biocompatibility - Verification

Posted by Josh Simon on Wed, Mar 28, 2012 @ 03:03

At the request of a fan of this site, I am devoting a post to Verification of biocompatibility of lubricious hydrophilic coatings.  Next article, I might talk a little bit about particulate and give an update on that, so stay tuned.

The first thing you need to do when looking into biocompatibility for a medical device, coated or not, is think about your application and categorize it on this chart:

biocompatibility chart

For most hydrophilic coatings, the application requires a Limited exposure (<24 hrs) in a Circulating Blood environment.  Therefore the chart reveals that you will need to do cytotoxicity, sensitization, irritation, systemic toxicity, in some limited circumstances genotoxicity, and finally, haemocompatibility.  If your application is different, look it up on the chart and see which tests you need.

First, make sure that your devices are tested exactly as they are delivered clinically, i.e. coated and sterilized.  You do not want to find out that your coating is fine but when sterilized it suddenly becomes cytotoxic, for example. 

The other thing you really should do is look at each bicompatibility test and understand how it works.  Do not just send out your samples with a checklist and rely on the results without thinking. 

For example, the cytotoxicity test can be complicated, and that's one of the simplest ones.  There are different variations on the MEM Elution test.  In the first phase, the test article is submerged in a fluid to extract substances into it.  This extraction can be done at different temperatures and for different lengths of time.  Obviously a longer extraction time at a higher temperature is the toughest test.  If you think you can pass the toughest test, go for it.  If you can't, then you just need to go for the test that is acceptable to the Regulatory body you work with.  In the second phase of the MEM Elution test, the extracted solution is exposed to cells, usually L929 fibroblasts.  This extraction can be done for different lengths of time too, from 24 hrs to 72 hrs.  The longer the exposure, the tougher the test.  Extractions can also be done with polar and non-polar solvents, and the tests can be run by weight or by surface area which has a big effect on the results.  Usually for hydrophilic coatings, you want to run the test by weight.

There are also vendor differences for these tests.  For example, they use different amounts of serum in their media, and some add antibiotics to the solution and some do not. Ask your testing vendor to see the protocols.  I am not able to conclude whether or not these protocol differences influence results but I can definitely tell you that different vendors give different results.  In my experience, Toxikon is really easy to pass, almost too easy, whereas Nelson Laboratories is tougher, but very reliable.  NAMSA is somewhere in between, and Apptec is probably on the tougher side.  Again, this is just my experience.  Your mileage may vary.

Generally, you should just figure out the minimum test protocol your Regulatory body will accept, and do that.  As long as in reality your device is not harmful to humans, you can rely on the results.

 

 

 

 

Tags: lubricious coating, biocompatibility, Regulatory, hydrophilic coatings, lubricious coatings, cytotoxicity

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

Pinch Testing White Paper Released

Posted by Josh Simon on Fri, Feb 24, 2012 @ 03:39

As promised, and not long after my last message, I present to you our newest white paper on Pinch Testing.  In its pages, you will come to understand what kinds of parameters govern the pinch test, with regard to hydrophilic coatings.

This paper is an attempt on my part to educate engineers in the field about how to choose a coating based on pinch test data.  For a few years now, I have encountered pinch test data from various companies that portray hydrophilic coatings in a durable and lubricious light.  The problem I saw with some of that data is that it was misleading.  In some instances, it did not give the conditions of the test.  Heck, it sometimes seemed like the authors of the data did not even know there were any test conditions in some cases.  They merely touted it as if it were sliced bread, but better.

That makes it rather difficult to tell the good coatings from the bad.  They are all more or less lubricous, but whether or not they can stand up to abrasion is not honestly portrayed in all cases.  It is my hope that this article would shed some light on that.

 

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Tags: Hydrophilic Coating, pinch tester, white paper, medical device development, pinch testing

Coatings odds and ends - From pinch tests to trade shows

Posted by Josh Simon on Thu, Feb 23, 2012 @ 01:46

There has been a flurry of activity this year that I am working to keep up with. 

Quite soon, I will be releasing an entire white paper based on my earlier blog article here, 5 Critical Questions to Ask About Pinch Testing. Do not worry about missing the release because you will see an announcement here, plus a press release, most likely.  From either of those sources you will be able to download the article.

We also just got back this week from the MDM West show in Anaheim, CA. With regard to hydrophilic coatings and related subjects, there was a lot of activity there.  Although I must note that Bayer's hydrophilic coating was conspicuously absent from their booth.  Maybe they finally read my blog articles on Hydrophilic Coating Market Size? There were also a few nice talks on plasma treatment of surfaces before coating, and another talk on cardiovascular-based applications by Dr. Ron Sahatjian of Medi-Solve.  To be honest, I could not attend either talk due to the traffic at my booth, and the schedule of meetings I kept that week.  If anyone wants to remark on them, feel free.

This is a little shot of the "Biocoat crew" from the show.

Biocoat Hydrophilic Coatings

Left to Right:  Dhruv Patel, Peg Beavers, Keith Edwards, Josh Simon

Tags: pinch tester, medical device development, hydrophilic coatings, MDM West, hydrophilic coating market, hydrophilic coatings blog, pinch testing, plasma treatment

Biocoat to exhibit hydrophilic coatings at MDM West - Anaheim 2012

Posted by Josh Simon on Wed, Feb 08, 2012 @ 03:21

As the title says, Biocoat will be exhibiting in Booth #1393 at the MDM West show in Anaheim this year from February 14th to 16th.

Feel free to reserve an appointment with me if you wish to consult about upcoming hydrophilic coating projects, or just stop by the booth and say "hi".

 

Booth #1393

Tags: news, MDM West

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

Hydrophilic Coatings Market Misinformation

Posted by Josh Simon on Wed, Jan 04, 2012 @ 01:46

Happy New Year!  As we start another year at the Hydrophilic Coatings Blog, I want to wish everyone a prosperous and successful year.

Lately I have noticed several firms trying to estimate the size of the hydrophilic coatings market, which is a subset of the medical coatings market.  Previous articles as well as ongoing updates to the data exist on the subject by big names like JP Morgan, Frost & Sullivan, the BBC, and others.  Most of these reports agree with BCC Research (HLC049B) which puts the market for medical coatings at US$5.3 billion in 2010, growing at 10% annually.

I am here to tell you that number is probably wrong, and off by perhaps an order of magnitude or more.

First let's break the medical coatings market down into segments.  Here's how I would do it:

Lubricious Hydrophilic Coatings

Drug Delivery Coatings 

Antimicrobial Coatings

Hydrophobic and other barrier coatings

Of course this is simplified because there is some overlap between these areas.  For example, you can have a lubricious drug releasting hydrophobic coating too.  Nevertheless, follow my logic here.

 

Let's take a look at publically available information on Surmodics and its deal with Cordis to provide a drug delivery coating for the now-defunct Cypher stent.  The quarterly minimum royalty paid by Cordis to Surmodics is $1,000,000.  (This is from Surmodics' latest 10-K form.)  In its heyday, Surmodic's received roughly 30% of its roughly $70 Million/year revenue from Cordis, which means about $21 Million.  So, I will stress again, the revenue to Surmodics on that was $21 Million/year, while Cordis' revenue for Cypher at its peak was way more than that.  For argument's sake, let's say it was $1 Billion.

Researchers that write these marketing reports do not seem to understand that there is a difference between $21 Million and $1 Billion.  The stent market contribution from Cordis at that time was perhaps $1 Billion, but that $1 Billion does not count towards the drug delivery coating market.  Instead, you should use the $21 Million, which is the revenue to Surmodics.

Now think about this.  If every single stent company licensed a swanky new drug delivery coating from a coating company like Surmodics, what would the total revenue be for that?  If there were 10 such stent companies, and they were twice as successful as Cordis ever was, you would have a $420 Million market for drug delivery coatings.  That's probably a generous estimation.

Now add in all the other coating types to that.  Hydrophilic coatings are not drug delivery coatings.  They do not bring in as much revenue.  Trust me if I say that a "really decent" customer can potentially bring in $1 Million/year in hydrophilic coating revenue at an industry standard 2% royalty rate.  Granted, few customers are that decent, but let's pretend they are.  Surmodics claims to have 100+ licensees, so let's pretend that all of them are hydrophilic customers that are "decent", and now let's pretend that there's 5 major players in that market:  Surmodics, Biocoat, DSM, AST, and Harland.  If each one of those companies is bringing in $100 million per year, that's another $500 million for the hydrophilic coatings market.  Since we all know what Surmodics' revenue is, and it's not $100 Million (and it's not all from hydrophilic coating sales), you know that this is wishful thinking.  From the math, you can also see that we haven't even reached $1 Billion yet for market size ($420 Million + $500 Million = $920 Million).

Suffice to say, if you calculate out hydrophobic and antimicrobial coating markets, you will not come up with the other $4.3 Billion put forth by BBC, and again I think this is because they do not differentiate between revenue to the coating company versus revenue that a completed device on the market fetches an OEM.

 

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Tags: hydrophilic coating market