Aseptic Production 4

Question 1

What is aseptic production?

Answer 1

• Manipulation of sterile ingredients or products
• Using sterile equipment
• Using appropriate techniques
• Clean room environment
-to maintain state of asepsis

Question 2

Clean Rooms • Walls and ceilings

Answer 2

• Walls and ceilings
– Moulds most common flora
– Feed off the plaster
Clean Rooms
– Should be smooth, impervious and washable
– Generally clad with laminated plastic
– False ceilings common to contain air filtration systems and light fittings
– Electrical wiring, pipework etc should be installed in cavity wall and sealed flush to surface

Question 3

What do clean rooms maintain?

Answer 3

asepsis

Question 4

Clean rooms

• Floors and drains

Answer 4

– Floors flat, impervious to water and easy to clean
– Floor joints adequately sealed
– Floor : wall junction coved (curved laminated plastic)
– Surface must be able to withstand cleaning products
– There should be no open sinks or drains in the clean room

Question 5

Clean Rooms • Doors, windows and fittings

Answer 5

– Must be fitted flush with the walls to prevent dust collecting
– Doors must be well fitting to prevent ingress by microorganisms
– Doors must be easy to open
– Windows for light only, not ventilation
– Fittings, such as door plates (not handles) must be easy to clean

Question 6

Clean rooms

• EU Guidance gives four grades of air:

Answer 6

– Grade A: for high risk operations e.g. aseptic connections, filling
– Grade B: minimum background environment for grade A zones
– Grades C and D: less critical stages of aseptic production e.g. labelling, packing

Question 7

Air Quality at rest

Answer 7

Maximum permitted number of particles/m3 equal to or above - At rest

0.5um
A: 3520
B: 3520
C: 352,000
D: 3,520,000

5um
A: 20
B: 29
C: 2900
D: 29,000

Question 8

Air Quality in operation

Answer 8

Maximum permitted number of particles/m3 equal to or above - In operation

0.5um
A: 3520
B: 352, 000
C: 3,520,000
D: not defined

5um
A: 20
B: 2900
C: 29,000
D: not defined

Question 9

Air supply

Answer 9

• Air introduced through HEPA filter

* 20‐35 air changes per hour (depends on room size, activity and number of operators)

Question 10

What is a HEPA filter

Answer 10

dust trapping filter

Question 11

• Different air flow patterns:

Answer 11

– Unidirectional

– Non‐directional

Question 12

Unidirectional air flow

Answer 12

• Grade A and B
• air comes in and goes through two sets of HEPA filters
• have a curtain of air usually from a ceiling
• air forced to floor in room, becomes turbulent around people
• air extracted through vents and is pumped out of the room and is then re-circulated through HEPA filters

Question 13

Non‐directional Air Flow

Answer 13

• Grade C and D
• where the air is usually drawn in from the outside rather than re-filtered, drops through a HEPA filter. Get very turbulent air. Don’t get a curtain and particles are more likely to be blown up than down
• Cheaper unit to fit

Question 14

High‐efficiency Particulate Air (HEPA) filters

Answer 14

• Pleated fibreglass with large surface area (pleating allows air to flow through filter at a high rate so don’t get a blockage)
• Exhibit
– High flow rate
– High particulate holding capacity 
– Low pressure drop across the filter

Question 15

HEPA Filters remove..

Answer 15

• Remove large particles by inertial impaction (onto fibre glass and stay)
• Remove medium particles by interception (by the very fine needles of fibre glass)
• Remove small particles by Browninan diffusion (motion of the air itself that causes the particles to be filtered out)
• Must conform to BS5295

Question 16

HEPA filters disadvantage

Answer 16

need cleaning and replacing regularly

Question 17

HEPA filters - interception drawing

Answer 17

bounce over one fibre but hit another

Question 18

Room Pressurisation

Answer 18

-to ensure particles leave room rather than enter
Clean rooms generally operate under positive pressure
– 10‐15 pascals above surrounding environment
– Prevents ingress of particles
– Multiple rooms have multiple pressure differentials
• Negative pressure (10‐15 pascals below surrounding environment) used if products deemed to be a risk to operators (used mostly for cytotoxic production - have to go from a dirty environment into a clean room then into negative pressure)

Question 19

Laminar Air Flow Cabinets - 2 types

Answer 19

• Similar to fume hood, in a fume hood you are extracting air but in LAFC the air is being pushed into the cabinet
• Horizontal Laminar Air Flow cabinet
• Vertical Laminar Air Flow cabinet

Question 20

Horizontal Laminar Air Flow cabinet

Answer 20

For products with no risk to operator e.g. TPN
• Open front
• HEPA filter in back of cabinet
- keep movements at minimum

Question 21

Vertical Laminar Air

Flow Cabinet

Answer 21

• For products with some risk to operator e.g. Cytotoxic drugs
• Perspex barrier
• HEPA filter in top of cabinet
-narrow operating window 
-unidirectional downward air flow

Question 22

What environment does a laminar air flow cabinet have to be in?

Answer 22

LAFC has to be in Grade B environment in the background but Grade A inside LAFC

Question 23

Isolators

Answer 23

• are closed boxes and are much more economical in terms of cost of environment and can be placed in grade D but isolator themselves are more expensive than LAFC

Question 24

2 types of isolators

Answer 24

Type I
• Positive pressure
• Protects product from operator and aseptic process
• Used for non‐ harmful production – TPN, injections, eye drops

Type II
• Negative pressure (equivalent to vertical LAFC)
• Protects product from operator and process and protects operator from product
• Used for cytotoxics, BCG

Question 25

How to tell difference between positive or negative pressure isolator

Answer 25

if positive gloves will push outwards, if negative will go into the isolator

Question 26

Isolators - Half‐suit isolator

Answer 26

• Rigid or flexible film
• Type I or type II
• Allows the operator greater movement
• Generally used in large scale manufacture - not used in hospitals

Question 27

Clean room clothing

Answer 27

• Prevents particulate contamination from the human body
• Must not shed particles or fibres
• Must be washable (for economic reasons)
• Must be sterilisable (usually autoclaving or radiation)

For autoclaving fabric needs to stand high temperatures

Question 28

Maintaining Asepsis

Answer 28

• Operator conduct
• Good technique is essential
– Staff training, validation and revalidation
• Appropriate disinfection of products (liberal amounts of alcohol used, should be left for sufficient amount of time to evaporate)
• Microbiological monitoring
– Finger dabs
– Settle plates (to catch stray particles - settle plates of blood agar)
– Surface testing (on a daily basis, swabs taken and cultured)
– Active air sampling (air is monitored constantly, hand held devices will suck in air and count particles)

Question 29

Asepsis and GMP

Answer 29

• GMP applies to all aseptic processes
• Must have a system in place to trace patients should a problem be identified
• Documentation kept up to date
• All processes to be validated regularly

Question 30

What can go wrong?

Answer 30

• Manchester Children’s Incident 1994
– 2 children died after receiving TPN contaminated with Enterobacter cloacae
• Germany Incident 2010
– 3 babies died and 4 critically ill after receiving TPN
contaminated with Enterobacter cloacae

• Giving lines were not changed regularly so bacteria appeared