Validation and Monitoring of sterilisation procedures

Question 1

what is parametric release

Answer 1

release based on compliance to physical specifications and validated procedures, rather than sterility testing

Question 2

when can parametric release be achieved

Answer 2

can be achieved when the kinetics of microbial inactivation are understood and the process variables may be accurately measured and recorded

Question 3

what are the considerations when designing a process

Answer 3

1. adequate premises
2. qualified personel who have undergone necessary training
3. suitable production equipment
4. minimising the bioburden before sterilisation is performed
5. validated procedures for all of the critical production steps
6. environmental monitoring
7. in process monitoring

Question 4

what is meant by validation

Answer 4

demonstrating that a procedure will consistently result in the intended outcome

Question 5

what needs to be validated in terms of sterility

Answer 5

both the sterilisation process and its effect on the product should be validated

Question 6

what can deviation from the specified process lead to

Answer 6

risk of non sterile product and deterioration of the product

Question 7

when is revalidation required

Answer 7

when any changes to procedure are made

Question 8

what are the goals of validation

Answer 8

1. suitability of the process
2. uniformity of the process
3. reproducibility of the process

Question 9

what information is required for validation of a process

Answer 9

1. commissioning data
   - equipment installation according to specifications
   - equipment safe to use
2. performance qualification data
   - equipment produces product with acceptable assurance of sterility
   - physical performance qualification
   - biological performance qualification

Question 10

what are the requirements for product release

Answer 10

1. documented procedures for product handling have been followed
2. the process conforms to sterilisation specification
3. facilities correctly maintained, routinely checked
4. load and packaging have not been damaged by processing or transportation
5. all sterilisation cycles were correctly and completely documented

Question 11

give examples of physical indicators

Answer 11

• heat distribution
• steam purity
• pressure
• time
• delivered dose
• relative humidity

Question 12

how are chemical indicators used

Answer 12

1. convenient to use but don’t provide any indication of microbial killing
2. based on the ability of steam, heat, gases and ionising radiation to alter the properties of the indicator when satisfactory conditions are met
3. some integrate a number of parameters
4. some indicate only 1 parameter

Question 13

how is Brownes tubes used as an indicator

Answer 13

multivariable indicator
- temperature and time
produces a colour change

Question 14

how is ethylene oxide used as a chemical indictor

Answer 14

• indicator paper with reactive chemical
• produces colour change in response to gas concentration, temperature, time, with a minimum relative humidity requirement

Question 15

how is the Bowie-Dick test used as an indicator

Answer 15

• saturated steam
• used to indicate air removal from porous load sterilisers
• uniform colour change indicates successful air removal and absence of air leaks

Question 16

give an example of a process indicator and how it is used

Answer 16

autoclave
- indicates exposure to a process but not whether it was successful in terms of sterilisation
- single point indicator (temperature)

Question 17

what are biological indicators

Answer 17

test systems containing viable microorganisms (usually spores of bacteria) that provide a defined challenge to verify the effectiveness of a specified sterilisation process

Question 18

what should be considered in the choice of using a biological indicator

Answer 18

1. advantage over chemical indicators- provide evidence of microbial lethality
2. agents should exhibit an above average resistance to the sterilisation process

Question 19

where are biological indicators placed

Answer 19

placed at strategic sites, those least accessible to the sterilisation process

Question 20

describe the interpretation of biological indicators

Answer 20

1. after the process, indicators are incubated in sterile medium and growth is monitored
   - no growth= successful process

Question 21

what are biological indicators characterised by

Answer 21

name of organism, strain number, viable spores per carrier and the D value

Question 22

how can indicators be used as a biological challenge for filtration sterilisation

Answer 22

indicators used as a challenge to the filter to demonstrate a sterile filtrate

Question 23

which indicator is chosen for the biological challenge for filtration sterilisation in 0.22um filters

Answer 23

pseudomonas diminuta chosen for its small dimensions

Question 24

which indicator is chosen for the biological challenge for filtration sterilisation in 0.45um filters

Answer 24

serratia marcescens