LOW-DOSE RADIATION STERILIZATION

Phase I study and recent results demonstrated that (1) polypropylene (PP) monofilament and polyglycolide (PG) braided sutures can be sterilized by 5 and 7.5 kGy gamma radiation in sealed packages in the presence of minute amounts of radiolytically controlled formaldehyde (CH2O) precursors; (2) under radiochemical sterilization (RC-S) conditions described in 1, in vitro and in vivo suture properties of PP and PG are not significantly compromised; (3) in typical RC-S cycles, minutes amounts of unstabilized Celcon-M90 can radiolytically produce sufficient CH20 to sterilize contaminated and uncontaminated sutures and spore strip controls; and (4) Celcon power can be used as a source of sterilizing formaldehyde and a slow absorbent for excess CH20 in the package, resulting in insignificant quantities of residual CH20 in sterilized packages. Phase II objectives are to (1) optimize RC-S conditions to achieve device and spore strip sterility at a dose of less than or equal too 5 kGy, while attaining a practically CH2O-free gas environment in the package; (2) develop the RC-S process in concert with package development for broad application to several forms of devices comprising absorbable and non-absorbable radiation-sensitive parts; and (3) conduct studies to support installation of self standing (or shared) contract RC-S facilities in Phase III. Phase II plans entail (1) optimizing the RC-S process for use with absorbable sutures and allied devices at less then or equal too 5 kGy toward selecting a practical combination of Celcon weights and device holders; (2) extending RC-S applications to absorbable orthopedic devices; (3) validating the RC-S process for typical commercial and selected experimental sutures, orthopedic, and related products; and (4) developing plans with a radiation technology partner to construct a self-standing (or shared) RC- S facility for precise delivery of less than or equal too 5 kGy radiation to prepackaged products in Phase III.