- In pharmaceuticals alert and action limits are very important, because these limits are effective control to the process.
- alert and action limits are in house limits, these limits must be less than guideline limits or define limits.
- Alert and action limits defined based on trend analysis.
- alert and action limits are like a barrier before the guideline limits.
Alert Limit:
- To be alert the microbial counts reach to this alert level.
- It is nor necessary to take any action.
- Possible deviation from normal process condition
- This is a trigger, that something is going wrong means microbial count increasing that area.
Action Limits:
- When microbial count reach this action limits then action is mandatory.
- To control the microbial count in the area.
- Signal an apparent deviation from normal process condition And require immediate action.
- If not controlled, we might get area failure.
These alert and action limits must be less than final limits.
Example :
Active air sample Grade -C Final limit 100.(as per EU -GMP,WHO-GMP, D&C schedule-m and PIC/s).
to establish the alert limit based on trend analysis - 20
to establish the action limit based on trend analysis - 24
Model -1
Sigma basis limits.
Alert Level
Alert
Level = Average +2 X Sigma
Ex: Average limit = 11.28
Standard Deviation (sigma)
=4.16
= 11.28 + 2 X 4.16
=20
Action Level
Action
Level = Average + 3 X Sigma
Ex:
Average limit = 11.28
Standard Deviation (sigma) =4.16
=11.28
+3 X 4.16
=24
Model-2
Alert Levels :
= Avarage +3√avarage-std deviation
Ex:
9 + 3√9
= 9+ 3 x 3
=18
Action
levels:
= Alert
limit +3 √alert
limit-standard deviation
=18 +3 √18
=18+
3 x 4.2
=
30
Ex :
1st Day
|
2nd Day
|
3rd Day
|
||
PWB001
|
12
|
14
|
14
|
|
PWB002
|
11
|
19
|
10
|
|
PWB003
|
10
|
20
|
12
|
|
PWB004
|
7
|
6
|
11
|
|
PWB005
|
4
|
8
|
10
|
|
Average
|
8.8
|
13.4
|
11.4
|
|
Average =
8.8 + 13.4 + 11.4 / 3 =
|
11.2
|
|||
Standard Deviation:
(8.8-11.2)2 = 5.76
(13.4-11.2)2 = 4.84
(11.4-11.2)2 = 0.04
=√5.76 + 4.84
+ 0.04 /3-1
= 1.63
