What are the 2 general approaches for sterilisation?
- Produce under ‘CLEAN’ conditions, then terminally sterilise in the final container
- Produce and assemble under conditions FREE of microorganisms and other particulates (ASEPTIC PROCESSING) – more prone to contamination, not as reliable
Which sterilisation option is preferred by manufacturers?
Option 1 - producing under clean conditions, more reliable
What are the microbial contaminants within the manufacturing environment?
Raw materials
Water
Manufacturing environment
What are raw materials?
- Synthetic/semi-synthetic (low levels of microorganisms)
- Natural - own intrinsic flora, greater levels of microorganisms
What is the primary requirement for microbial growth?
Water - prone to microbial contamination
What is included in the manufacturing environment?
- Air (acts as a vector)
- Personnel
- Equipment and facilities
What are the sources of resident organisms?
- Soil (gram positive)
- Water (gram negative)
- Animals and humans - gram+ve/-ve
- Plants - yeasts and moulds
What are the sources of transient organisms?
Carried by water and air (vectors)
What is the definition of sterile?
free of viable microorganisms (absolute term – either sterile or contaminated, can’t use ‘quite sterile’)
What is the definition of sterilisation?
process by which we eliminate – killing or removal of all viable microorganisms
What are the methods for ‘killing’ sterilisation ?
o Moist heat sterilisation (safest, easiest and most reliable) – in presence of steam, excess of 100 degrees
o Dry heat sterilisation – in oven, absence of moisture for materials denatured by moisture
o Radiation sterilisation – cobalt 60 used for heat sensitive products
o Chemical – ethylene oxide sterilisation
What is a method of ‘removal’ sterilisation?
Filtration – choose porosity carefully to remove cells
What are sterilisation standards?
- Control the number of microorganisms in the manufacturing environment – guidance
- Validate sterilising agent – experimental data that shows effectiveness (e.g. of heat)
- Validate sterilisation process
- Monitor sterilisation process
- Regulated by: EN, FDA etc
