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

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

Dental and Orthopedic Applications for Hydrophilic Coatings

Posted by Josh Simon on Wed, Dec 21, 2011 @ 02:53

I am not going to say this is a hopeless cause, because there could always be that device out there that could benefit from a slippery hydrophilic coating that I have not seen yet.  However, if you think about dental and orthopedic applications in relation to hydrophilic coatings and/or lubricious coatings, I am generally not enthusiastic when approached by these companies.

Mainly, what I am thinking about right now are bone screws and plates for bone repair, and dental implants for prosthetic dentistry.  To analyze this, I want you to ask yourself what sorts of environmental conditions are these devices exposed to?

Essentially, these are implantable medical devices, so everything I said in my previous article on implantable hydrophilic coatings applies. That is to say that polymeric hydrophilic coatings will degrade or be abraided off during insertion.  A hydrophilic coating made from your typical polyurethane, polyacrylic, pvp, or hyaluronan would not have the strength to withstand those shear forces.  A research version of a titanium-based hydrophilic coating exists which might be good for this sort of application, except that it has no commercial sales that I can find, and could literally be years or a decade away from commercialization.  This also means that I cannot find anything about its mechanical or frictional properties.  Thus, for now, we are stuck with polymeric coatings.

Even more strangely, I recently got a call from an entrepreneur seeking to coat a calcium phosphate-based bone void filler with hydrophilic hyaluronan.  Unfortunately, he could not tell me why.  Everything I know about bone growth into scaffolds tells me this should not be done because if you inhibit clotting in the porous matrix, you can inhibit formation of the fibrin matrix that eventually houses the osteoblasts that will eventually lay down bone.  More thought needs to be put into some of these applications.

If instead you are thinking about temporary disposable instruments, like a replaceable tip for a knee scope, or a minimally invasive surgical canula, you may be in luck.  Devices that are disposable and not implanted might indeed benefit from a lubricious hydrophilic coating.

 

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Tags: lubricious coating, Hydrophilic Coating, dental, orthopedics, hydrophilic coatings, lubricious coatings, hyaluronic acid, hyaluronic acid coating

Implantable Hydrophilic Coatings

Posted by Josh Simon on Mon, Nov 21, 2011 @ 03:59

In a previous blog post on permanent hydrophilic coatings, I noted that really all hydrophilic coatings have some sort of bioerosion, degradation, and/or resorption rates in vivo.  For most coatings of this nature, those rates are high, which means they are not always suitable for implantation.

Honestly, that's a rather broad and general statement about the utility of implantable hydrophilic coatings.  In reality it goes back to a question I like to ask a lot on this blog:  What is your application?

Let me break that out into some more specific thought questions:

What kind of device do you want to coat?

WHY do you want to coat it?

Do you want it to be slippery?  Non-thrombogenic?  Closely associated with water to prevent fogging or misting?

Given your answer to the question above, exactly WHEN do you want the coating to possess those properties during the life of the device?  Pre-implantation? During implantation?  During explantation?  The whole time?

Given that last answer, how long is that time period?  Minutes?  Hours?  Days?  Weeks?  Forever?

In many cases, for example in the case of an implantable cardiac pacemaker, surgeons may be complaining that it is difficult to squish the leads into place during the procedure.  A lubricious coating might help with that.  However, once the device is implanted, who cares about what happens to the coating as long as it is biocompatible?  Or maybe I should ask:  do you care what happens?

If you do care, then you need to ask yourself why.  Is there some other function a slippery, non-thrombogenic, water-loving coating will serve a purpose after implanting that pacemaker?

Most of the time, when clients come to me asking for permanent hydrophilic coatings, it actually turns out that they do not need them to be permanent.  They just need them to fulfil a temporary role, which the coating can do easily, and then when it goes away it is of no consequence.

 

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Tags: advanced coating, lubricious coating, medical device coating, Hydrophilic Coating, biomaterials, hydrophilic coatings, lubricious coatings, non-thrombogenic coating

Hydrophilic Coatings at MDM Minneapolis 2011

Posted by Josh Simon on Wed, Nov 09, 2011 @ 02:56

The guys at Medical Design Technology filmed me while I was at our booth for the MDM Minneapolis show this past week giving a lubricious hydrophilic coating demonstration.

 

I want to especially thank Mr. Sean Fenske, Editor-In-Chief at MDT magazine for doing this.

Tags: lubricious coating, Hydrophilic Coating, hydrophilic coatings, coating video

Hydrophilic Coatings vs. Hydrophobic Coatings

Posted by Josh Simon on Fri, Oct 14, 2011 @ 09:02

An article I wrote for Med-Tech Innovation back in April that covers the crucial differences between hydrophilic and hydrophobic coatings is now open to the public.  Until now it was somewhat paywalled behind a free subscription.  So, if you have not yet looked at it, head over there and take a look now!

 

Tags: lubricious coating, Hydrophilic Coating, hydrophobic coating, hydrophilic coatings, lubricious coatings

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

Hydrophilic Coatings on PTFE

Posted by Josh Simon on Mon, Aug 08, 2011 @ 10:39

I have posted an entry as a Guest Blogger on Medical Design Magazine's Perspectives blog.  To understand more about why you would not want to coat a hydrophilic coating with TeflonĀ®, see my article on coating PTFE.

 

Teflon structure

Tags: lubricious coating, hydrophilic coatings, lubricious coatings, Teflon, hydrophilic coating on PTFE, hydrophilic coating on teflon, hydrophilic coatings blog

A Lubricious Coating That Has Dry Lubricity

Posted by Josh Simon on Tue, Jun 14, 2011 @ 11:04

Here is another question that comes up sometimes:  Do you have a coating that is lubricious when dry?

dry lubricityMore often than not, these questions come from non-medical professionals who want to use the coating for a piece of machinery, rather than a biomaterial which interacts with a living system.  In other cases, the device is for a machine that is used as part of a medical device that has moving parts.

The easiest answer to this question is "no", because hydrophilic coatings accomplish their mechanism through formation of hydrogels on a microscopic level, which closely associate electrostatically with water and lower friction.

The more precise answer is actually a question:  What do you mean by lubricious?  How slippery is slippery enough?  Ok, that is two questions.

Let's put things into perspective and talk about coefficient of friction on a surface.  The coefficient of friction of teflon is about 0.2 to 0.3.  The coefficient of friction of ice is about 0.01 to about 0.1.  The coefficient of friction for most hydrophilic coatings for medical devices ranges from 0.01 to about 0.1 also.  Some hydrophobic coatings like Parylene have coefficients of friction ranging from 0.25 to about 0.4.

If you want a coating that has a coefficient of friction in the 0.01 to 0.05 range while dry, you are basically out of luck. You may want to try a lubricant like silicone oil.  On the other hand, if friction in the range of 0.2 to 0.3 is ok for you, then you want teflon or parylene.  The drawback there is that these are hydropobic not hydrophilic.

In some cases, there are hydrophilic silicones that can have coefficients of friction around 0.2.

Tags: lubricious coating, Hydrophilic Coating, parylene, hydrophilic coatings, lubricious coatings, silicone spray, dry lubricity