Widespread efforts under way today to replace polyvinyl chloride (PVC) in medical applications are largely a waste of resources and energy, says Len Czuba, the president of his own product development firm, Czuba Enterprises Inc.
PlasticsToday interviewed Czuba on what he considers the most significant trends taking place today in medical plastics.
|Czuba is a former president of the Society of Plastics Engineers.|
An abridged version of the interview follows:
PT: What are the biggest trends you see in medical plastics?
I'm actively involved in organizing conferences for the Society of Plastics Engineers and MD&M, and I see tremendous interest in bioresorbables. One example is the Abbott Vascular bioresorbable cardiovascular stent that is now in clinical trials in Canada. Bioresorbable screws and anchors have been used for a while with very good success. I think that's a hot market that will continue to grow. There are three big producers and they can pretty much tailor the resorption rates to whatever is needed.
PT: What materials do you see as the key players for bioresorbables? PLAs? Animal derivatives?
PLAs and the various copolymers available. People want to get away from animal-derived materials. There's a movement away from animal derivatives in additives already.
PT: What are the challenges with bioresorbables?
The big challenge is how do you successfully or easily process them. They easily degrade and they are very expensive, above $1000 a pound.
PT: Are high costs in general an issue for implantable plastics?
Victrex considers PEEK not so much as a plastic material, but as more of an orthopedic material. They won't even sell it to the molders; they will only sell it to the OEMs and let the molders use it on a consignment basis. It costs more than $1000 per pound. In some respects they can justify the high costs of some of these materials. But on the other hand I saw that Solvay is no longer willing to supply their standard grade of materials (for implant applications). They are now coming up with a special implantable grade as a replacement for what they used to use. I believe that it is wrong for them to use the need for implants opportunistically and believe it is abusive to users who have successfully used this same material for years. I find this an offensive business decision. They've gone from a polysulfone that cost less than $30 a pound, even less than $20 a pound, to charging $750 or more a pound. I also wish Invibio (Victrex's medical business) would become more reasonable with their pricing. The whole issue is, does the material really justify that kind of pricing? They could probably sell it for half of what they are selling it and still make a tremendous profit.
PT: What about efforts by hospital to phase out use of PVC for intravenous bags and tubing. Do you think that's a legitimate issue?
I don't. I'm still looking for legitimate science to indicate we should change, and so far I'm not finding it. People somehow got the idea that PVC is bad and the snowball started rolling and became an avalanche. I think there are three or four specific products that require non-DEHP PVC because the amount of extraction of the plasticizer is higher than is normally the case for drug infusion. I'm not convinced it is necessary, but I would say if you want to be on the safe side, go ahead and use alternatives.
PT: What about studies that are said to show that DEHP plasticizer can be an endocrine disrupter for infants?
It hasn't been proven. No one knows that for sure that the extracted phthalate plasticizer is the direct cause for noted effects. It's the same as people raising concerns about bisphenol A coming out of polycarbonate. Is it a concern? One researcher has been the primary antagonist, and most people who have looked into the issue and done studies are not concerned about it. If there are problems with PVC or polycarbonate, we should make changes, but so far nothing has been proven, at least to my understanding. PVC is a good material. We're wasting a lot of time and effort trying to replace a good material.
PT: How good are the substitutes for PVC?
There are a lot of good materials out there, but for everyone I've seen there is a tradeoff in properties or cost. I think that clarity is extremely important as is softness. The materials that I have seen as replacements have less clarity, are less flexible and will be more expensive to manufacture, resulting in a higher-cost material. That's why I was so shocked when I read that companies like Kaiser Permanente are saving millions of dollars by switching to the replacements. I don't see it. We've asked for some proof of this; they don't provide it.
PT: Do you represent the PVC industry in any way, Len?
PT: There has been a lot of buzz about antimicrobials. What's your view?
I have mixed feelings about antimicrobials. I think they are good for some very specific applications. The way people are talking about them for across-the-board use, I don't think it's good. My concern is that when we tell people we are using antimicrobial products are we then leading them to be more lax in their care? That could be a concern because if products that are intended to be carefully swabbed and cleaned before use are not treated as carefully, might that not lead to more hospital-acquired infections?
PT: Do you feel that federal heathcare reform will have a positive or negative effect on the medical plastics business?
It's already having a dampening effect on business. From what I see, people are just holding their breath. It was similar to when (former president William) Clinton got to the White House and threatened a healthcare bill, everybody held off on investment spending. I see it to an even greater degree right now. The medical device tax is a cost that companies did not plan for. With costs becoming so tightly controlled, I think it will be more of a problem than a benefit.
PT: Thank you Len.
Shawn Shorrock, Solvay's global healthcare manager, made these statements to PlasticsToday in response to Czuba's comments:
"Our industrial medical grades of polysulfone have never been offered for implantable applications. We had a strict nonimplant policy for industrial-grade materials. Anyone using them for implantable devices did so at their own risk. Our polysulfone has a long history of use for medical device applications, such as hemodialysis. In 2007, we launched our Solviva biomaterials business for implantable applications. And when we did that, that's when we started offering our Eviva polysulfone for implantable medical applications. It was priced higher than industrial products because it's offered in a totally different way. It's manufactured on dedicated assets, with strict adherence to validation, traceability and control. The governing quality-management system is based in ISO 13485, the same quality manufacturing system that is used by medical device manufacturers. Six of the largest medical device manufacturers have audited our production system. They want these types of controls in place. Then we have done complete, extensive biological evaluation and chemical characterization of these materials. We maintain a Master Access File with the FDA to support regulatory submissions on these products. Responsible OEMs want materials with high quality, tight manufacturing controls, traceability, and know that using materials without these controls means the introduction of significant risks. The higher prices for these materials are justified by the higher costs to produce them.