Posted by
Josh Simon on Thu, Jan 26, 2012 @ 03:54 PM
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.
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.
|
Posted by
Josh Simon on Wed, Jan 11, 2012 @ 09:06 AM
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?
Posted by
Josh Simon on Wed, Jan 04, 2012 @ 12:46 PM
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.
Posted by
Josh Simon on Wed, Dec 21, 2011 @ 01:53 PM
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.
Posted by
Josh Simon on Mon, Nov 28, 2011 @ 08:18 AM
Today's article comes to us from Drs. Demetrius Chrysostomou and James Bond from PVATepla. It is an informative read on plasma treatment for hydrophilic coatings:
Catheters are inserted into the body for fluid drainage, duct dilation and drug/nutrient delivery. With an invasive device the host’s health can be compromised due to tissue trauma and subsequent infection. Hydrophilic coatings are beneficial in reducing trauma damage. However, some catheter polymers can be classified ‘difficult to coat’ and the adhesion is far from optimal. Good adhesion of the hydrophilic coating is essential. Poor adhesion could lead to shedding of the coating in vivo and increase the risk of coronary embolism. This is where plasma can play an important role
What is plasma?
Plasma is a gas energized to a state of electrical conductivity. Chemically it is a highly reactive environment that is used to change the properties of surfaces without affecting the bulk material. Plasma is a powerful tool in solving surface preparation problems such as precision cleaning and decontamination, increasing surface wettability and adhesion promotion of functional bio-molecules and coatings. Plasma can also be used to polymerize coatings onto surfaces through a technique called Plasma Enhanced Chemical Vapor Deposition (PECVD). The main advantage of plasma as an enabling technology is that it is a clean dry process. As such there are none of the liabilities of wet chemistry, such as leaching toxic solvents.
Historical use of Primers for Surface Activation
Historically primers have been used to activate ‘difficult polymer’ surfaces. Some primers are considered hazardous. There may be primers are highly toxic, caustic, carcinogenic and are potential leachables. The EPA and FDA review medical grade primers and the trend is to remove particular primers from the ‘safe to use list’. An example of the chemical primer used for PTFE and ePTFE is TetraEtch (a mixture of sodium, naphthalene and 1,2 – dimethoxyethane). This primer is teratogenic, toxic and caustic.
Plasma prepares the surface by molecular cleaning. Specific chemical groups are then grafted by a second plasma step. The surface is then exposed to the functional molecules that chemically bind to the plasma grafted moieties.
ePTFE use for medical devices
Expanded polytetrafluoroethylene (ePTFE) is a commonly used material for implant applications. It’s mechanical strength, impermeability to blood and inertness to bio fouling make ePTFE ideal for such in-vivo applications. Its flexibility aids in healing, and catheter tubing doesn’t kink very easily and generally has good compression resistance. For biomedical applications the ability to modify PTFE surfaces is important to promote interfacial biocompatibility.
Plasma treatment of ePTFE for binding lubricous coatings
It is possible to graft polar functional groups to PTFE by plasma activation. These polar functional groups act as excellent anchor to covalently bond hydrophilic coatings. The PVA TePla plasma surface activation for ePTFE is an environmentally friendly alternative to primer treatment. We treat parts in a highly controlled low temperature, low pressure dry, clean gas environment such as the IoN300 catheter treating tool below.
What does PVA TePla America offer?
PVA TePla America offers a solutions based team of chemists (physical, surface, organic and bio-chemist) who will work with you or your chosen coatings company to find the very best surface treatment for you polymer. We offer free proof of process as an incentive to evaluate our plasma technology. We have clean area contract processing capability with ISO 9001:2008 certification. And we offer a full range of vacuum and atmospheric gas plasma systems. PVA TePla America is based in Corona, CA. www.pvateplaamerica.com
For further information contact jamesb@pvateplaamerica.com (951) 415-0391
Posted by
Josh Simon on Wed, Nov 23, 2011 @ 09:38 AM
I found an interesting article talking about Bayer's coating business and its increased focus on the Chinese market. Let me point out that the business of "coatings" is gigantic and comprises everything from paint, to industrial coatings, aerospace surfaces, and yes, even medical device coatings. In this article, Bayer is talking about moving a multiple hundreds of million (perhaps over a billion?) dollar operation in a market just as large.
By contrast, hydrophilic coatings are an almost infintesimally small part of the overall business of "coatings". Bayer does indeed have a hydrophilic coating it obtained when it bought the business from Lombard Medical. However, I am not sure that Bayer yet realizes that this market is infintesimally small compared to its other businesses.
In my guestimation, the entire market for hydrophilic coatings, in the world, is not over $120 million. (Although it is definitely growing fast.) You have to remember, this is not medical device revenue. This is revenue for hydrophilic coatings sold to the medical device companies that eventually put them on products. Effectively, what a hydrophilic coating company sells is a "bottle of stuff", or a "bottle of goo", as Peg Palmer is often fond of saying. How much money you can get for goo is limited to whatever license fees, royalties, or direct revenue you can get for it. Unless you capture the entire market, your realistic expectations are likely to be smaller than the rounding error of one of Bayer's typical products.
Posted by
Josh Simon on Mon, Nov 21, 2011 @ 02:59 PM
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.
Posted by
Josh Simon on Wed, Nov 09, 2011 @ 01:56 PM
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.
Posted by
Josh Simon on Fri, Oct 14, 2011 @ 08:02 AM
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!
The Crucial Divide between Hydrophobic and Hydrophilic Coatings
Also do not forget that recently I did a webinar on hydrophilic coatings and hydrophobic coatings. As a quick refresher, remember that most hydrophilic coatings take the form of a bilaminar surface treatment. Check out this image:
Posted by
Josh Simon on Thu, Oct 06, 2011 @ 02:54 PM
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.
