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Sterilization of Medical Devices

Gaseous chlorine dioxide (CD) was extensively studied as a sterilant for Medical Devices by both Abbott and Johnson & Johnson in the 1990’s. Both companies saw significant advantages of CD for sterilizing medical devices and performed successful testing on surgical kits, suture products, artificial joints, interocular lenses, and may others. Fast forward to today’s environment with EtO facility shortages and potentially explosive 100% EtO mixtures rather than the blended Oxyfume of the past and the need for an EtO replacement is more urgent than ever. In December of 2019, the FDA requested ClorDiSys to present on our CD technology in Washington DC. Similar to EtO, our CD process is registered as a sterilant with the US EPA (registration number is #80802-1) and our NJ facility is also registered with the FDA as a Contract Sterilization facility (Registration #3013115071). The CD process can also be brought back in-house to save both costs and shipping time. Most Medical Device manufacturers do not want to perform in-house sterilization utilizing EtO because of the liabilities of having a carcinogenic and explosive compound on site. The cost of a system, including the Damage Limiting Construction (DLC) featuring walls that are built to explode outward and Class 1 Div. 1 electrical installation, is extremely expensive. A CD system on the other hand has none of those costs or liabilities. Cycles are quick and simple being as short as a couple of hours in many cases. No special rooms for extensive aeration are required.
ClorDiSys is easy to work with and can assist with both Cycle Development and Validation to enable the use of CD to be as simple as possible. CD is very similar to EtO in how it is utilized, the type of devices that can be sterilized, and the SAL sterilization levels that can be attained. An integrated UV-VIS spectrophotometer measures and controls the gas concentration ensuring the efficacy of every cycle and allowing for parametric release. Both are gasses but CD is not explosive or carcinogenic and leaves no harsh residues. CD cycle times are much shorter. ClorDiSys has a draft Device Master Reference file available as a guide. Devices can be packaged in Tyvek pouches, display boxes, or final shipping containers. Final corrugated shipping containers require a significantly more robust cycle. CD is friendly to most materials and electronics.


Contract Sterilization of Medical Devices In-House Sterilization of Medical Devices

Chlorine dioxide is the method usually recommended when devices have imbedded batteries which are not affected by CD. CD does not get absorbed into materials like EtO does, so an aeration time of under 30 minutes is typical. Chlorine dioxide is a true sterilant gas and works at true ambient temperature. The boiling point of CD is low, at -40°C. CD gas will not condense on devices. It is a surface sterilant, therefore CD gas can sterilize prefilled syringes, while maintaining drug integrity, and medical devices with complex geometries.


CD is also not listed as a carcinogen. In almost all locations, it can simply be exhausted to the environment rather than needing to be scrubbed with hazardous solutions. It is non-flammable and non-explosive at use concentrations, so it does not require expensive damage limiting construction.


In-house treatment costs can be as low as $5 per load.

Chlorine Dioxide Gas Molecule Size


Surgical Kit

The CD Gas Advantage

Chlorine dioxide gas sterilization is ideal for sensitive biotech products and improves supply chain efficiency:


  • ClorDiSys' CD Gas is an EPA registered sterilant, making it effective against all viruses, bacteria, fungi and spores

  • Non-carcinogenic

  • Ambient temperature sterilization (0°C - 50°C) - can be customized for unique applications

  • Adjustable vacuum levels - can be customized for unique applications

  • Surface sterilization process - does not get absorbed in most materials for quicker aeration

  • Short cycle times - 2 to 8 hours including aeration

  • Safe and easy to bring in house - reduces manufacturing time and cost

Aerates Rapidly - Minutes vs. Days

Properties as a non-vapor, surface sterilant with a low boiling point, coupled with the low CD sterilant concentrations, translates into rapid aeration of the sterilization chamber and exposed products.CD does not permeate or become absorbed in materials to the same degree as other methods, greatly reducing the overall cycle time of the sterilization process and eliminating the lengthy post-sterilization aeration.


Low Residue Levels

CD’s properties combined with the rapid aeration process results in residues below detectable levels on product and packaging. CD’s sterilant residues are non-carcinogenic, non-cytotoxic and non-teratogenic. Sterilized packages and products may be handled immediately after the cycle.


Flexible to Design Custom Cycles

Process Parameter Range
CD Gas Concentration From 1 mg/L to 20 mg/L
Exposure Time Varies with Application
Door-to-Door Time 2-8 Hours
Relative Humidity Typically 65-90%
Depth of Vacuum 5-101 kPa
Chamber Temperature Ambient to 50°C

Compatible with Medical Device Materials and Packaging

Artificial Joints

CD is less oxidative than traditional oxidizing sterilants like hydrogen peroxide, ozone, NO2 and peracetic acid. ClorDiSys has tested many medical device materials including non-ferrous metals, polymers, batteries, tissues, bone products, and collagens. Compatible materials showed no increase in cytotoxic response. The true room temperature performance of the CD process allows temperature sensitive materials to be processed.
CD’s sterilization process is compatible with commonly used sterile barrier packaging. This includes: non-woven polypropylene, Tyvek® pouches, Tyvek®-Mylar® pouches, plastic tubs with Tyvek® lids as well as cellulosic materials such as paper and cardboard.



Compatible Materials*
Stainless Steel
Aluminum
Copper
Glass / Ceramic
Fluoropolymers
Most gasket materials
Polyethlene
Polypropylene
PET / PETG
Polystryene
Polysulfones
PEEK
Polyetherimide
Polycarbonate
Cycline Olefins
PVC
Silicone
Hypalon
Thermoplastic Elastomers
Titanium
Gold
Platinum
Cardboard
Most Inks
*This list is not exhaustive. Specific testing with your device is always recommended.

Current Applications

Below is a list of applications that CD gas has been used for. Please contact us for more information on any of these applications or to explore additional applications not listed below.

Sample Applications
Implantable Contact Lenses
Artificial Joints
Suture Products
Bones and Bone Powders
Surgical Kits
Datwyler Stoppers
Endoscopes
Electronic Devices