CTFAS Regulations

Question 1

For stability testing, how many lots are used?

Answer 1

3 lots may be used following the drug testing principle

Question 2

What are the 4 basic tests of stability testing?

Answer 2

1. Accelerated stability testing
   - predict long term behaviour
2. Confirmatory stability testing/ real time stability testing
   - monitor state of product
3. Interaction with package (compatibility testing)
   - glass is typically used as reference
4. Microbiological

Question 3

What are the 4 types specialised/stress tests?

Answer 3

1. Temperature cycling/freeze thaw test
2. Mechanical and physical test
   - vibration test to see if shipping movements affect
3. Light stability
4. Low RH (relative humidity) testing
   - in case package is water permeable

Question 4

5 main microorganisms concerned in cosmetics?

Answer 4

1. Pseudomonas aeruginosa (bacteria)
2. Escherichia coli (bacteria)
3. Staphylococcus aureus (bacteria)
4. Candida albicans (yeast)
5. Aspergillus brasiliensis (molds)

Question 5

What are microbiological limit tests?

Answer 5

It tests on raw materials and final products to assess and to detect if there’s any primary contamination during manufacturing

Question 6

What are microbiological challenge tests?

Answer 6

Tests on final products to assess preservation efficiency for preventing secondary contamination due to consumer uses (mimic condition of consumer uses)

Question 7

What are microbiological in-use tests?

Answer 7

Tests to confirm preservation efficiency for preventing secondary contamination (not mandatory)

Question 8

How do we conduct microbiological limit tests? (2 methods)

Answer 8

1. Pour-plate method
   Dispense 1g or 1ml of test samples & 15-20ml of agar medium onto dish & mix well -> colony counting
2. Agar plate method
   Add 0.1ml of test sample & spread sample diluents well -> colony counting