Chlorine dioxide gas sterilization of cold-chain or temperature-sensitive devices

Cold-chain terminal sterilization is used for products that must be manufactured, stored, and maintained with a carefully controlled temperature range, such as temperature-sensitive drugs and vaccines in prefilled syringes or autoinjectors containing temperature-sensitive drugs. Chlorine dioxide (ClO ₂ ) is an ideal sterilant for cold-chain terminal sterilization because it forms a true gas at room temperatures (15°C/59°F - 25°C/77°F), with a reliable and consistent process with excellent penetration and does not require elevated temperatures. In the current study, we validated the efficacy of ClO2 on cold stored pre-filled syringes as well as tested ClO ₂ -sterilized samples and non-sterilized controls for residual sterilant on the prefilled syringe samples and the ingress of sterilant into the prefilled syringe samples. Residual sterilant remaining on a load after sterilization could cause chemical exposure to patients and negatively affect healthcare worker safety, among other things. Sterilant ingress into a medication could result in chemical contamination, drug degradation, and changes to drug formulation. Few studies have been published on ClO ₂ residue or ingress during terminal sterilization. We demonstrate that chlorine dioxide sterilization leaves residuals and ingress amounts at acceptably low levels. ClO ₂ sterilization is an excellent alternative to ethylene oxide sterilization for cold-chain sterilization because it is sustainable, non-carcinogenic, and does not leave harmful residuals, nor does it ingress into the drug product.