How do pathogens harm the patient?
Cause infectious disease
How do microbes damage a product?
Degrade API, make dose unpalatable
Which routes of administration have the greatest and least infection hazards?
- Parenteral has the greatest risk
- Then cream (skin is sensitive)
Oral has the least risk - stomach acid kills bacteria
Which order is microbe growth?
First order = logarithmic
What does CFU stand for?
Colony forming unit = 1 live microbe
What is Decimal Reduction Time (D)?
Time taken for a 10x reduction in microbes (i.e. 90% reduction in concentration)
What is the sterility assurance level (SAL)?
Level of sterility required for terminally sterilised products = 10-6
- Therefore the probability of an item being non-sterile if selected at random should be 1 in 1,000,000
How is sterilisation time for an item decided?
Based on decimal kill rate (D) value
How is sterility tested?
- Take a sample from the item (swab, liquid or filtrate)
- Add to culture medium
- If no growth after 14 days = non-sterile
Totally killing all microbes on product/item
Cleaning a surface
What does a disinfectant do?
Kills microbes on a surface
What does an antiseptic do?
Kills microbes on skin/tissue
What does a microbicide do?
What does a bacteriostatic drug do?
Stops growth of bacteria
List 2 methods by which heat is used as a sterilisation technique?
- Dry heat
List 2 advantages of using heat as a sterilisation technique?
- Steam is very effective
List disadvantages of using heat as a sterilisation technique?
- Wets product/dries product out
- Can damage product
What application is there for using filtration as a sterilisation technique?
Solutions for injection
List 2 advantages of using filtration as a sterilisation technique
- Good for liquids/solutions
- Removes particles
List 2 disadvantages of using filtration as a sterilisation technique
- Only good for solutions
What application is there for using chemical sterilisation?
Surfaces and equipment
List 2 advantages of chemical sterilisation
- Very effective
List 2 disadvantages of chemical sterilisation
- Usually needs to be removed from the product afterwards
- May damage product
List 2 examples of irradiation used for sterilisation
List 2 appllications of where irradiation can be used as a sterilisation technique
- Packed products
List 2 advantages of irradiation as a sterilisation technique
- Quick and cheap
- Penetrates packet
List 2 disadvantages of irradiation as a sterilisation technique
- Surface only
What is the disadvantage of using gas as a sterilisation technique?
Hazardous to workers
What piece of equipment is used for steam sterilisation?
What are the conditions within the autoclave?
- High pressure
- 15-30 minutes
How does the autoclave/steam kill bacteria?
Hydrolyses the proteins
What is dry heat sterilisation used for?
- Typically for surgical instruments
- Hot enough to char off some components
What are the conditions of dry heat sterilisation?
- 2 hours
Define: Terminal sterilisation
When the product is sterilised at the start and at the end
Define: Non-terminal sterilisation
When product is sterilised throughout the manufacturing process
List 3 chemicals used for sterilisation and how they work
Phenols - disrupt membrane and denature proteins
Alcohol - denature proteins and dissolve membranes
Aldehydes - crosslinks biomolecules, one of the most effective disinfectants
List 4 conditions which influence the effectiveness of antimicrobial agents
Type of micro-organism
Concentration of micro-organisms
Environmental conditions (pH, viscosity)
Which is harder to kill - gram negative or gram positive bacteria?
List 2 other processes that occur during the production of sterile products