Recent Advancements Address Regulatory Requirements for Monitoring of Cleanrooms
Viable air monitoring is a crucial part of
an environmental monitoring program.
Because common viable air monitoring
methodologies have not been introduced
in many years, monitoring in critical
manufacturing areas like Grade A, RABS
and isolators creates a dilemma for the
Traditional methods lack the necessary
sensitivity. Singular results only provide an
indicator of cleanroom status; often there
is no direct correlation between number
of organisms and product contamination
A defensible monitoring program should
be based on the following criteria:
- Frequency of testing: Frequent/
- Location: Close to critical points
- Performance: Without adding any
contamination risk to the product
With most traditional methods, it is
virtually impossible to achieve a defensible
monitoring program. Manufacturers
frequently disregard the fact that handheld
instrumentation contributes to particle
load of an area and causes flow turbulences
close to manufacturing. Mobile devices
cannot be properly sterilized for use in
Grade A environments.
For process security, viable air monitoring
devices that can sample remotely into ISO
Grade 5 areas must be installed. In the near
future, international inspectors will not accept
any handheld devices in critical areas.
When remotely sampling very close to
critical control points, a risk assessment
can determine whether the manipulation
and cleaning procedures for the
remote atriums used impose a risk to the
patient or the product. Knowing that, in
many cases, the risk cannot be correctly
assessed, as traditional viable air sampling
techniques do not produce realistic views
of the environment, manufacturers may
consider the use of single-use air sampling atriums to drastically reduce operator
handling close to the critical zone. A
risk-based approach includes the use of
real-time viable air testing during media
fill (process validation) exercises, enabling
the manufacturer to map the full critical
process in real-time operation.
There are two options to ensure the full
manufacturing process is continuously
monitored with data generated: single-use
and real-time technologies.
Single-use technologies have been validated
for long-term, two-hour sampling
in critical environments at 25 LPM. In
an eight-hour process model, this relates
to only four sampling units covering the
full manufacturing process for viable air
sampling, limiting the need to frequently
interfere with the process.
Continuous viable air sampling can also
be managed by a real-time monitoring device
instrument. Data accumulated by this
instrument better equips manufacturers
with a full understanding of the manufacturing
environment and allows for immediate
action when critical concentrations
of biological counts are reached. Lines can
be stopped, material waste avoided, and
quality assurance dramatically increased
with a perceptible decrease in production
loss and cost.
Real-time viable measuring tools not only
capture culturable microorganisms, but
also viable, nonculturable microorganisms,
well known in the pharmaceutical
industry to be a risk not controlled by
current sampling technologies. As a result,
counts of those technologies are generally
higher in contaminated areas, but
zero counts are also possible in critical
environments. When moving to these
technologies, it is possible for manufacturers
to detect some biological counts where
previously zero CFU with traditional
methods would be common. Regulators
indicate that the primary advantage of
better process control could be attained by occasionally finding a biological count
in areas where it is not expected. Incidents
of biological counts in critical areas
are detected almost regularly, but strong
deviations from this trend and frequency
indicate in real time whether the process is
out of control and needs to be readjusted.
As with particle monitoring, a correct
selection of alert and action limits must
be based on a risk assessment and a
consistent amount of trending data. ISO
14644-2 recommends the selection of a
reasonable alarm notification strategy, not
based on a single-event triggering alarm,
but on a combination of multiple out-ofspecification
counts over a period of time.
The main goal of selecting the appropriate
alert/action alarm strategy is essential to
avoid nuisance alarm events that could be
ignored by operators (2).
A disadvantage of real-time viable
monitors is the fact that identification of
contaminants is not possible due to the
nature of the detected microorganisms.
Therefore, pharmaceutical manufacturers
are advised to combine real-time viable
testing with a continuous viable monitoring
approach. With this combination,
the safety of the drug and process will be
moved to a higher standard, protecting
patients from microbial contaminations.
Regulatory Concerns Justify New
With the introduction of modern
manufacturing concepts and an increasing
number of industry standards, there
is a need to adopt viable air monitoring
in conjunction with the most recent
regulatory trends (3). Regulations provide
specifications for the selection of a viable
air monitoring strategy.
ISO standards are becoming more important
as a reference for the pharmaceutical
industry. The EU GMP Annex 1 explains
that ISO/EN norms should be considered
as reference documents when it comes to
detailing methods for the determination of microbiological and particulate cleanliness
of air, surfaces, etc. (4).
The ISO 14698 standard states that “a
sampling device shall be selected according
to the area being monitored” (5).
Looking at the expected concentration of
viable particles in different clean zones,
in critical areas like Grade A/ ISO 5 with
expected low to zero counts of microorganisms,
high sampling volumes or
continuous sampling is preferable (1,4,6).
the EU GMP Guide supports this:
“Where aseptic operations are performed
monitoring should be frequent using
methods such as settle plates, volumetric
air and surface sampling” (4). Also, U.S.
regulations state “sample sizes should
be sufficient to optimize detection of
environmental contaminants at levels that
might be expected in a given clean area”
(7) and “routine microbial monitoring
should provide sufficient information to
demonstrate that the aseptic processing
environment is operating in an adequate
state of control” (8).
Under European guidelines, “for Grade
A zones, particle monitoring should be
undertaken for the full duration of critical
processing” (4). Particulate matter not
only consists of inert, nonviable particles,
but also viable particles. Continuous
monitoring of viable particles should be
undertaken for ISO 5/Grade A cleanroom
When considering risk zones, manufacturers
typically focus on Grade A/ISO
5 areas, and not the overall cleanroom
concept, which includes Grade B, C and
ISO 7 zones. Contaminations in areas surrounding
ISO 5 can significantly contribute
to product/patient contamination risk;
thus, similar monitoring plans should be
considered when selecting the instrumentation
for those environments.
Both U.S. and European regulatory
guidelines and ISO standards outline the
need for routine monitoring of cleanrooms.
Using single-use and real-time
technologies in conjunction offers a way
to address these requirements by bringing
manufacturing processes to a greater level
- Saghee, R., Sandle, T. and Tidswell, E. (2011).
Microbiology and Sterility Assurance in Pharmaceuticals
and Medical Devices. New Delhi: Business
- ISO 14644-2. (2015).
- Guidance for Industry: PAT — A Framework
for Innovative Pharmaceutical Development,
Manufacturing, and Quality Assurance, 2004,
- EU Guidelines to Good Manufacturing Practice.
(2008), Volume 4, Annex 1
- ISO 14698-1. (2003).
- ISO 14644-1. (2015).
- Guidance for Industry: Sterile Drug Products
Produced by Aseptic Processing - Current Good
Manufacturing Process, 2004, U.S. FDA
- USP 39 NF 34. (2016). Microbiological Control
and Monitoring of Aseptic Processing Environments.
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