Key checklist of WHO TRS 1044-annex-2
For products that have been filled aseptically, samples should include containers filled at the beginning and end of the batch. Additional samples (for example, taken after critical interventions) should be considered based on risk.
For products that have been heat sterilized in their final containers, samples taken should be representative of the worst-case locations (for example, the potentially coolest or slowest to heat part of each load).
Note: Where the manufacturing process results in sub-batches (for example, for terminally sterilized products), then sterility samples from each sub-batch should be taken and a sterility test for each sub-batch performed.
The sampling locations of filled units before sterilization should be based on a worst-case scenario and be representative of the batch.
Any organisms found during bioburden testing should be identified and their impact on the effectiveness of the sterilizing process determined.
The bioburden assay should be performed on each batch for both aseptically filled product and terminally sterilized products and the results considered as part of the final batch review. There should be defined limits for bioburden immediately before the final sterilizing grade filter or the terminal sterilization process, which are related to the efficiency of the method to be used. Samples should be taken to be representative of the worst-case scenario (for example, at the end of hold time).
Microorganisms detected in the grade A and grade B areas should be identified to species level and the potential impact of such microorganisms on product quality (for each batch implicated) and overall state of
control should be evaluated.
Microbial monitoring of personnel in the grade A and B areas should be performed.
Monitoring should include sampling of personnel at periodic intervals during the process.
To monitoring personnel involvement in critical interventions (at a minimum gloves but may require monitoring of areas of gown as applicable to the process) and on each exit from the grade B cleanroom (gloves and gown). Where the monitoring of gloves is performed after critical interventions, outer gloves should be replaced prior to continuation of activity. Where the monitoring of gowns is required after critical interventions, each gown should be replaced before further activity in the cleanroom
Continuous viable air monitoring in grade A (for example, air sampling or settle plates) should be undertaken for the full duration of critical processing, including equipment (aseptic set-up) assembly and critical processing. A similar approach should be considered for grade B cleanrooms based on the risk of impact on the aseptic processing.
Viable particle monitoring should also be performed within the cleanrooms when normal manufacturing operations are not occurring (for example, post disinfection, prior to start of manufacturing, upon completion of the batch and after a shutdown period)
In case of an incident, additional sample locations may be used as a verification of the effectiveness of a
corrective action (such as cleaning and disinfection).
The grade A area should be monitored continuously (for particles ≥ 0.5 and ≥ 5 µm) and with a suitable sample flow rate (at least 28 litres per minute) so that all interventions, transient events and any system deterioration is captured.
Procedures should define the actions to be taken in response to alarms, including the consideration of additional microbial monitoring
For grade A, particle monitoring should be undertaken for the full duration of critical processing, including equipment assembly.
If alert limits are exceeded, operating procedures should prescribe assessment and follow up, which should include consideration of an investigation or corrective actions to avoid any further deterioration of the
environment. If action limits are exceeded, operating procedures should prescribe a root cause investigation, an assessment of the potential impact to product (including batches produced between the monitoring and
reporting) and requirements for corrective and preventive action.
Risk assessments should be performed in order to establish this comprehensive environmental monitoring programmed, such as sampling locations, frequency of monitoring, monitoring methods and incubation
conditions (such as time, temperature, and aerobic or anaerobic conditions)
These risk assessments should be reviewed regularly in order to confirm the effectiveness of the site’s environmental monitoring programme. The monitoring programme should be considered in the overall context of the trend analysis and the CCS for the site.
The selection of monitoring locations and the orientation and positioning of sampling devices should be justified and appropriate to obtain reliable data from the critical zones.
Both viable and total particle alert levels should be established based on results of cleanroom qualification tests and periodically reviewed based on ongoing trend data
Both viable and total particle alert levels should be established based on results of cleanroom qualification tests and periodically reviewed based on ongoing trend data
depyrogenation tunnels -Air pressure difference profiles should be established and monitored.
Critical process parameters that should be considered during validation or routine processing should include:
i. Belt speed and dwell time within the sterilizing zone.
ii. minimum and maximum temperatures;
iii. heat penetration of the material or article;
iv. heat distribution and uniformity;
v. airflows determined by air pressure differential profiles correlated with the heat distribution and penetration studies.
Critical process parameters that should be considered in qualification or routine processing should include:
i. temperature;
ii. exposure period or time;
iii. chamber pressure (for maintenance of overpressure);
iv. air speed;
v. air quality within the oven;
vi. heat penetration of material or article (slow-to-heat spots);
vii. heat distribution and uniformity;
viii. load pattern and configuration of articles to be sterilized or depyrogenated, including minimum and maximum loads.
Moist heat sterilization can be achieved using steam (direct or indirect contact), but also includes other systems such as superheated water systems (cascade or immersion cycles) that could be used for containers that may be damaged by other cycle designs (such as BFS containers or plastic bags).
For porous cycles (hard goods), time, temperature and pressure should be used to monitor the process and should be recorded.
For steam-in-place systems, the temperature should be recorded at appropriate condensate drain locations throughout the sterilization period.
Validation of porous cycles should include a calculation of equilibration time, exposure time, correlation of pressure and temperature, and the minimum/maximum temperature range during exposure. Validation of
fluid cycles should include temperature, time and F0.
Leak tests on the sterilizer should be carried out periodically (normally weekly)
Distortion and damage of non-rigid containers that are terminally sterilized, such as containers produced by BFS or FFS technologies, should be prevented by appropriate cycle design and control (for instance, setting
correct pressure, heating and cooling rates and loading patterns).
The system should be monitored for temperature, pressure and time at appropriate locations during routine
use to ensure all areas are effectively and reproducibly sterilized. These locations should be demonstrated as being representative of, and correlated with, the slowest to heat locations during initial and routine validation.
In fluid load cycles where superheated water is used as the heat transfer medium, the heated water should consistently reach all of the required contact points. Initial qualification studies should include temperature
mapping of the entire load. There should be routine checks on the equipment to ensure that nozzles (where the water is introduced) are not blocked and drains remain free from debris.
Sterilization – Where possible, the finished product should be terminally sterilized, using a validated and controlled sterilization process, as this provides greater assurance of sterility than a validated and controlled sterile filtration process and/or aseptic processing.
Validated loading patterns should be established for all sterilization processes and load patterns should be subject to periodic revalidation. Maximum and minimum loads should also be considered as part of the
overall load validation strategy.
Heat sterilization cycles should be revalidated with a minimum frequency of at least annually for load patterns that are considered worst case. Other load patterns should be validated at a frequency justified in the CCS
Where biological indicators are used to support validation or to monitor a sterilization process (for
example, with ethylene oxide), positive controls should be tested for each sterilization cycle.
The reliability of biological indicators is important. Suppliers should be qualified and transportation and storage conditions should be controlled in order that biological indicator quality is not compromised. Prior to use of a new batch or lot of biological indicators, the population, purity and identity of the indicator organism of the batch or lot should be verified.
For other critical parameters (such as D-value or Z-value), the batch certificate provided by the qualified supplier can normally be used
Indicators – such as autoclave tape or irradiation indicators – may be used, where appropriate,
to indicate whether or not a batch (or sub-batch material, component or equipment) has passed through a sterilization process.
These indicators show only that the sterilization process has occurred; they do not indicate product sterility or achievement of the required sterility assurance level.