SBIR-STTR Award

When people with diabetes reach end-stage renal disease they must undergo either dialysis or transplantation. About 200,000 Americans need artificial kidney machines to stay alive. These machines rely on sterile dialysis membranes to remove toxic materials from the bloodstream. More than 30 different polymers or polymer blends are used in dialysis membranes, and most of these degrade under conditions of steam or gamma radiation sterilization. Ethylene oxide (EO) remains the sterilant of choice for these membranes. However, the traditional blend used 88 percent CFC-12 as a fire suppressant and propellant, and CFCs have been phased out of production because of their high ozone-depletion potentials (ODPs). Alternatives include explosive 100 percent EO and blends of EO with high global warming potential (GWP) hydrofluorocarbons (HFCs), less effective carbon dioxide, or hydro chlorofluorocarbon (HCFC) compounds facing future phase out. This proposed Phase I effort wilt determine the feasibility of using blends containing EO, trifluoromethyl iodide (CF3I), and HFCs for sterilizing dialysis membranes. Trifluoromethyl iodide is an excellent combustion suppressant and has physical properties similar to CFC-12 with zero ODP and extremely low GWP. Flammability and fractionation tests will be conducted to determine optimal blend compositions. Compatibility and residual CF3I measurements with common membrane materials will be conducted. PROPOSED COMMERCIAL APPLICATION: The research, if successful, will develop a new nonflammable sterilant gas for dialysis membranes that does not contain ozone-depleting substances, is more effective that current alternatives, and has reduced GWP. The new sterilant gas should also be useful for sterilizing many other types of medical equipment. The new sterilant gas should be marketable worldwide and should allow use of existing EO sterilizing equipment, thus reducing costs of medical care.

Thesaurus Terms:
antiseptic sterilization, artificial membrane, dialysis, ethylene, fluorohydrocarbon, iodine, technology /technique development composite resin

The overall goal of this SBIR effort is to develop for commercialization a new nonflammable, cost-effective, low atmospheric impact sterilant gas as a demonstrated and approved sterilizing agent for hemodialyzers and related equipment. The new sterilant gas should be marketable worldwide and should allow use of existing ethylene oxide (EO) sterilizing equipment, thus reducing costs of medical care. The new gas has been given the trade name IoxideTM . The cost of treating renal disease in the U.S. is constantly increasing. The total number of dialysis patients in the U.S. is currently about 290,000, and is expected to rise to about 520,000 by 2010. Medicare alone is already paying out about $11 billion per year for treatment of dialysis patients. Many dialysis membrane materials and other materials used in sensitive medical equipment degrade under the conditions of steam or gamma radiation sterilization. Currently explosive 100% ethylene oxide is being used to sterilize many dialyzers and other sensitive medical equipment, which increases the cost of sterilization. Cost-effective technologies are needed to reduce the cost of hemodialysis, as well as many other medical procedures. In Phase II, the low levels of residual Ioxide components in hemodialyzer materials will be verified; compatibility with a wide selection of materials used in sensitive medical equipment will be measured; a shelf-life will be determined; the suitability of catalytic oxidizers with Ioxide will be established; pilot production will be arranged; and the new sterilant will be demonstrated in sterilization of medical equipment. Residuals will be measured by thermal offgassing of components from hemodialyzers sterilized with Ioxide. Compatibilities will be determined by exposing material specimens to the new sterilant with subsequent visual inspection, size and weight measurements, and surface analysis. A minimum shelf life will be determined by maintaining Ioxide in typical storage containers over the project period. Small catalytic oxidizers will be operated with the new sterilant and their outgas analyzed to establish their suitability for use. Arrangements will be made with a chemical manufacturer to produce a pilot run of Ioxide. The pilot run will provide enough of the new sterilant for demonstrations of sterilization of medical equipment at one or more facilities.

Thesaurus Terms:
antiseptic sterilization, biomedical equipment safety, chemical synthesis, clinical biomedical equipment, gas, hemodialysis cost effectiveness, evaluation /testing, method development