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PROCESS Woldwide-PharmaTEC 01-2004
Purity in the pipeline
Fluoropolymers are strong candidates for pharma processing equipment

Today’s ever more demanding process environments and purity standards highlight inherent flaws such as corrosion, metallic contamination, brittleness, and biofilm adhesion. Non-corroding biofilm-resistant fluoropolymers are replacing traditional stainless steel and glass in the battle to maintain the purity of biopharmaceutical processing systems.

When Mrs. Smith buys a prescription drug over the pharmacy counter, she does so mainly with its curative effect in mind. She would be unaware of the battle waged by biopharmaceutical companies to maintain sterile conditions in the tubes and fittings that make up the typical fluid handling systems used by the industry – a battle against micro-organisms (biofilms) and other contaminants that could spoil the products she trusts so much. While the industry progresses rapidly into the 21st century with the development of increasingly sophisticated biopharmaceutical products, it is seeking ways to move beyond the limitations of the two principal 20th century materials used in the construction of process equipment – glass and stainless steel. Today’s ever more demanding process environments and purity standards highlight inherent flaws such as corrosion, metallic contamination, brittleness, and biofilm adhesion. Manufacturers must employ costly cleaning procedures to maintain hygiene in glass and stainless steel systems to comply with health, safety and environmental regulations.
Industry in transition Despite its timeworn traditions, the industry is turning to improved materials that offer important advantages. And fluoropolymers, led by DuPont Teflon PFA HP, are key to this transition. Today, widespread adoption of Cynergy Sanitary Systems of Teflon PFA HP, developed by Entegris of Chaska, Minnesota/USA, a leader in high purity chemical delivery and distribution systems, is evidence of the construction materials revolution. Brian Richards, European sales manager – Entegris Life Sciences, explains why. “Increasingly, leading biopharmaceutical companies are writing Cynergy systems into their fluid handling specifications. They are doing so based on the outstanding performance of fluoropolymers in the semiconductor industry, and on compelling evidence from research carried out by the University of Minnesota Bioprocess Technical Institute, and others. Those tests confirm that the non-corrosive non-wetting surface of Teflon PFA fluoropolymer releases contaminating biofilms virtually completely while the same biofilms (K. pneumonia, Salmonella S. Choleraesuis and E.coli) were significantly retained by stainless steel, borosilicate glass, polypropylene and polyvinylidene fluoride.” Contamination problem CP Pharmaceuticals of Wrexham, Wales, a manufacturer of branded and unbranded prescription pharmaceuticals, faced a serious contamination problem in its reverse osmosis water distribution system. Ultraclean water was stripping out plasticisers in the ABS (Acrylonitrile Butadiene Styrene) pipework, causing embrittlement and decay, and compromised compliance with United States Pharmacopoeia Class 24 (USP 24) regulations, essential to product distribution in the USA. The challenge was to find a new USP 24-compliant construction material that would eliminate contamination, while increasing system lifetime and capacity. The solution was provided by a completely new distribution system using Cynergy valves, fittings and beadless weld tubing of Teflon PFA HP. “The key advantages of our new pipework system over the industry standard 316L stainless steel and ABS – that of maintained water purity and increased system life – became apparent immediately”, reports Neal Frost, technical officer, CP Pharmaceuticals OLC (ointments, liquids and creams) Department. “We were influenced by scientific data showing that Teflon PFA HP does not encourage microbial growth. In practice, the smoother surface finish and lubricity of the fluoropolymer has led to higher flow and capacity, even though the new one inch tubing is only half the diameter of the old pipework. As a result, CP Pharmaceuticals has been able to save valuable space while lowering costs and maintaining water quality”, Frost confirms. Preserving purity A different problem faced Alcon Laboratories of Fort Worth, Texas/USA, an international manufacturer of ophthalmic eye solutions for prescription and over-the-counter use. The company discovered that silicone tubing used in its aseptic filling operation was absorbing a vital preservative from the eye solution. The challenge was to find an alternative tubing material that would prevent this loss and also meet exacting performance criteria. Two years ago Alcon replaced all the silicone tubing with Cynergy hose assemblies of FDA-approved Teflon PFA HP. The company reports that the system no longer absorbs any of the preservatives, thanks to the inertness of fluoropolymer, and the smooth non-stick inner surface is easier to clean and steam sterilize. Confidence rewarded Brian Richards of Entegris points to similar success stories at Baxter Healthcare, Bayer Biotech, GlaxoSmithKline and others. “These major companies cannot take risks with untried materials. They have chosen Entegris’ Cynergy Sanitary Systems of Teflon PFA HP to replace stainless steel, glass and alternatives, based on proven performance and the evidence of biofilm removal studies. Their confidence is rewarded by reduced production cost, less downtime for regulatory compliance procedures, and the highest process purity.” And Mrs. Smith can continue to sleep peacefully at night, whether she takes sleeping pills or not!kem
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