Clean Versus Sterile
Pharmaceutical Processing - November 2013
It is recognized that any medical device that punctures the skin or any medication that enters the bloodstream must be sterile, and sterilization procedures are reasonably well-established in the pharmaceutical and medical device industries. What may not be as well understood is that devices and medications should also be essentially free of particles (i.e. clean). Parenteral products (medication or nutrition introduced into the body via infusion, injection or implantation) must be both sterile and clean. Controlling unwanted particulate matter in products requires knowledge of potential sources of particles and processes that might generate particles to avoid potential problems. It is important to monitor the products through their lifecycle to maintain their integrity.
Sterilization is the process used to remove or kill any microbiological activity such as fungi, bacteria, viruses and spores on surfaces or in solution. Steam sterilization and sterile filtration are most commonly used in the pharmaceutical industry. The sterile filtration process involves passing the product through a 0.2 µm filter and has the added benefit of removing unwanted particulate that may be present. The filtration and filling processes are performed in cleanroom facilities to further reduce the chance of introducing particles. The containers (vials or syringe cartridges) are cleaned prior to filling. These processes are usually well-controlled and are very effective in reducing or eliminating unwanted particles in parenteral products. However, particles do slip through these stringent procedures, and on these occasions, the source of the problem needs to be identified.