FDA on chemicals leaching into the systemic circulation

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FDA Science Forum 1997

Supercritical Fluid Extractions (SFE) of Various Polymers Used In Medical Devices

http://vm.cfsan.fda.gov/~frf/forum97/97A17.htm,

Abstract A17

Supercritical Fluid Extractions (SFE) of Various Polymers Used In Medical Devices

Hoan­My Do Luu and Eyituoyo O.Ekperigin, DMMS, OST, CDRH, FDA,Rockville, MD 20852.

Polymeric biomaterials often contain additives that can be leached into the systemic circulation. These additives, mostly of unknown concentration, can produce adverse health effects over the lifetime use of the device. Our goal was to develop fast, efficient SFE methods for extracting total leachables from seven different polymer matrices including polyetherurethane (Texin, Miles Inc.), polyesterurethane (Tecoflex, Thermedics Inc.), polyvinylchloride (Geon 87402, Geon Co.), polymethylmethacrylate (Paraloid K­120, Rohm & Haas Co), ethylene acrylic acid (A­C Copolymer 5180, Allied Signal Inc.), cellulose acetate (Eastman Chemical, Inc.) and polydimethylsiloxane (Silastic GP 30, Dow Corning LTD). Extractions were run using a Suprex Prepmaster_system, which includes a dual pump and an AccuTrap with temperature controlled restrictor. The operating principles of SFE in many ways resembles a Soxhlet extraction except the solvent is carbon dioxide, a supercritical fluid, a substance above critical temperature (31°C) and pressure (75.3 atm). The maximum amount of leachables obtained for the seven polymers tested over a set of conditions (pressure, temperature, volume and flow rate) varied from 0.25 to 10% of the polymer weight.

Any amount of leaching is dangerous !

SBI's have some 40 chemicals that leach out into the tissues and blood of

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