Sterile Products

Question 1

Sterility

Answer 1

Absence of microorganisms

Question 2

Why give a drug by injection?

Answer 2

Rapid action
Localised action
Prolonged activity
Drug not active by other routes
Drugs degrading by oral route
Metabolised by oral route = low bioavailability

Question 3

Characteristics of the vehicle in injections

Answer 3

Pharmacologically inert
Non toxic
Non irritant liquid
Usually water for injection

Question 4

Pyrogens

Answer 4

Substances when administered to humans result in an increase in temperature

Question 5

Isotonic

Answer 5

Solutions with same osmolarity

Question 6

What happens when IV administration of hypotonic solutions (lower osmolarity than blood)?

Answer 6

RBC swelling and irreversible haemolysis

Question 7

Clean room

Answer 7

Concentration of airborne particles is controlled
Temperature, humidity and pressure are controlled

Question 8

Active monitoring

Answer 8

Air sampling
Contact plates
Finger dabs
Swabs

Question 9

Grade B clean rooms temp and humidity

Answer 9

Temp of 18 +- 3
Humidity 45+- 15%

Question 10

Why is Clean room clothing needed

Answer 10

Outermost layer of skin sheds
Approx 1% carries bacteria

Question 11

Separation device

Answer 11

Some form of barrier between the device and surrounding clean rooms

Question 12

Isolators

Answer 12

Used for sterility testing, aseptic filing…
Arrangement of physical barriers that are integrated

Question 13

Restricted access Barriers (RABs)

Answer 13

Open passive RABs utilise existing clean room overhead air supply systems to deliver filtered air
Closed RABs is a positive pressure system with on board fan/filtration units to supply filtered air over the critical process before being recirculated

Question 14

Terminally sterilised

Answer 14

Sterilised in the final container

Question 15

Non terminally sterilised

Answer 15

Not sterilised in final container, but prepared under aseptic conditiond

Question 16

Methods of sterilisation : heat

Answer 16

Microorganisms lose their viability

Question 17

What is the heat resistance of different microorganisms

Answer 17

Vegetative bacteria, viruses and fungi= hot water at 60-100
Spores= >100

Question 18

Autoclave

Answer 18

Sterilisation by saturated steam under pressure

Question 19

Saturated steam

Answer 19

Water vapour in equilibrium with water
Temp of steam corresponds to the boiling point of the water producing it
Releases latent heat of vaporisation on condensing

Question 20

What indicators can you use in an autoclave

Answer 20

Chemical and biological indicators

Question 21

Biological indicators

Answer 21

Must come with a certificate of conformity
Should indicate the population, D value and purity of the microorganisms

Question 22

Chemical indicators: Bowie and dick test

Answer 22

A test of the effectiveness of the air removal scheme
Indicator turns dark if it was properly sterilised ( all air was removed)
If the indicator changes colour, it wasn’t subjected to the required time/ temp (121C for 15 mins)

Question 23

Advantages of autoclaving

Answer 23

Terminal sterilisation
Any dose volume
Good safety margin
Viruses killed
Relatively short progress
Suitable for dressings, rubber, some plastics
Suitable for solutions and suspensions

Question 24

Disadvantage of autoclaving

Answer 24

Unsuitable for heat unstable materials
Unsuitable for anhydrous materials (oil and powders)
Organisms killed but not removed
Skilled operators required
May damage glass and metal
Batch process

Question 25

Dry heat

Answer 25

Water absent from the heating environment

Question 26

Hot air oven

Answer 26

Electrically heated
Insulated chamber and doors
Fan to ensure air circulation
Heat transfer by convection and radiation
Temp variation should not exceed 5

Question 27

Applications of dry heat

Answer 27

Heat stable items, either sensitive to moisture or impermeable to steam
High temps to sterilise and depyrogenate glassware
Anhydrous materials (oils, fats, non aq)
Glass and metal-waders
Some rubbers

Question 28

Advantages of dry heat

Answer 28

Terminal sterilisation
Any dose volume
Viruses killed
For anhydrous materials
Suitable for solutions and suspensions
Less damage to glass and metal than moist heat
Suitable for some assembled equipment

Question 29

Disadvantages of dry heat

Answer 29

Drastic heat treatment
Organisms killed but not removed
Unsuitable for dressings, rubber and plastics
Suspensions may give a different crystal form on cooling

Question 30

D value (decimal reduction value)

Answer 30

Time required to produce a tenfold reduction in no. Of viable organisms

Question 31

Bioburden

Answer 31

Number of organisms present on a surface or in a sample before sterilisation

Must achieve 10^-6