Environmental Monitoring Considerations

Nancy Roscioli, Ph.D.

Don Hill and Associates, Inc.

Environmental Monitoring Components

• Airborne nonviable particulate monitoring

• Airborne viable contaminant monitoring

• Viable contaminant monitoring of surfaces

• Viable contaminant monitoring of personnel

• Temperature and humidity monitoring

• Pressure differential monitoring

Environmental Monitoring Components

• Water monitoring:– Total organic carbon– Conductivity– Microbial Contaminants– Endotoxin

General Environmental Monitoring Considerations

• Monitoring frequencies and strategies– Establishment of a meaningful and manageable

program

• Sampling and testing procedures

• Establishment of effective alert and action limits

• Trending of results

General Environmental Monitoring Considerations

• Investigation and evaluation of trends as well as excursions from alert and action limits

• Corrective actions to be implemented in response to environmental monitoring excursions

• Personnel training - sampling, testing, investigating excursions, aseptic technique

Scope of Environmental Monitoring Program

• Should include monitoring of all environments where products and their components are manufactured– All areas where there is a risk of product

contamination

• Should include monitoring of all water used for product manufacturing as well as feed water to the final water purification system (WFI System)

Regulatory Basis for Environmental Monitoring Program

• CFR GMP regulations

• FDA Guidance Documents

• USP Informational Chapter

21 CFR 211.42

• Aseptic processing areas:– Easy to clean and maintain– Temperature and humidity controlled– HEPA filtered air– Environmental monitoring system– Cleaning and disinfecting procedures– Scheduled equipment maintenance and

calibration

21 CFR 211.46

• Ventilation, air filtration, air heating and cooling:– Adequate control over microorganisms, dust,

humidity and temperature.– Air filtration systems including prefilters and

particulate matter air filters for air supplies to production areas.

Guideline on Sterile Drug Products Produced by Aseptic Processing

• Defines critical and controlled manufacturing areas

• Recommends airborne nonviable and viable contaminant limits

• Provides some guidance on monitoring frequencies for critical areas

Guideline on Sterile Drug Products Produced by Aseptic Processing

• Recommendations for air pressure differentials

• Includes guidance on aseptic media fills

• Note: This guidance document was written in 1987 and is in need of revision

Microbial Evaluation and Classification of Clean Rooms and Clean Zones

• USP General Information Chapter <1116>

• Establishment of clean room classifications– Federal Standard 209E

• Importance of EM program

• Personnel training in aseptic processing

• Establishment of sampling plans and sites– suggested sampling frequencies

Microbial Evaluation and Classification of Clean Rooms and Clean Zones

• Establishment of alert and action limits

• Suggests limits for airborne, surface and personnel contaminant levels.

• Methods and equipment for sampling

• Identification of isolates

• Aseptic media fills

• Emerging technologies - barrier; isolator

Federal Standard 209E

• “Airborne Particulate Cleanliness Classes in Clean Rooms and Clean Zones

• Approved by the GSA for use by all Federal Agencies

• Frequently referenced for controlled environment particulate requirements: Classes 100, 10,000 and 100,000 (based on particles > 0.5µ)

Guidance for Industry for Sterile Validation Process Validation in Applications for Human

and Veterinary Drug Products• Scope limited to final drug product manufacturing

and data required for application submission (NDA, BLA)

• Requests information on:– Buildings and facilities– Manufacturing operations for drug product

• Filter validation• Validation of hold times

Guidance for Industry for Sterile Validation Process Validation in Applications for Human

and Veterinary Drug Products• Requests information on:

– Sterilization and depyrogenation– Media fills and actions taken when they fail– Microbiological monitoring of the environment

• Airborne microorganisms, personnel, surfaces, water system, product component bioburden

– Yeasts, molds, anaerobes– Exceeded EM limits

Viable and Nonviable Contaminant Limits

Nonviable (>0.5µ) Viable (CFU)Classifi-cation ft3 m3 ft3 m3

Class100

100 3,530 0.1 3.5

Class10,000

10,000 353,000 0.5 18

Class100,000

100,000 3,530,000 2.5 88

Controlled Area

• Preparation or manufacturing area where nonsterile product, in-process materials and product-contact equipment surfaces, containers and closures are exposed to the environment

• Control nonviable and viable contaminants to reduce product /process bioburden

• Class 100,000 or Class 10,000

Controlled Area

• Capping areas are now considered controlled manufacturing areas– Should be supplied with HEPA filtered air– Should meet class 100,000 conditions during

static conditions

Critical Area

• Aseptic processing area where sterile products, components or in-process products are exposed to the environment and no further processing will occur.

• Air quality must be Class 100 during processing• Local Class 100 areas are often utilized during

open processing steps during drug substance manufacture.

Critical Area

• The area just preceding the sterile core should be one classification higher than the core.

Nonviable Particulate Monitoring

• Airborne cleanliness classifications should be met during operations

• Nonviable monitoring should occur routinely during operations

• Monitoring during static conditions is done as part of HVAC qualification and may be done periodically after that to insure area meets acceptable conditions before use or following cleaning

Nonviable Particulate Monitoring

• Locations for monitoring should be established during performance qualification; probes placed close to work surface

• Monitoring frequencies vary:– For aseptic processing areas, during each use– For other, controlled areas, varies from each

use to weekly or less depending on use of area

Nonviable Particulate Monitoring

• HVAC Validation and Maintenance Considerations:– Air velocity, airflow patterns and turbulence

should be validated; smoke studies to determine flow patterns during static and dynamic conditions

– HEPA filter integrity testing

– HEPA filter efficiency testing

– Air pressure differentials

Microbial Monitoring

• Airborne viable contaminants

• Surface contaminants– walls– equipment surfaces– countertops– floors

• Personnel contaminants

Microbial Monitoring

• Monitoring methods should be capable of detecting molds and yeasts

• Should also be able to detect anaerobes– Most often, this is an issue associated with

products filled anaerobically (with nitrogen overlay)

• All lots of media for EM sampling should be growth promotion tested

Microbial Monitoring

• Routine microbial monitoring should take place during operations (for airborne contaminants) and immediately following operations (for surfaces and personnel).

• Airborne monitoring frequencies:– Each use for aseptic processing areas– Varies from daily to weekly to less frequently

for controlled areas depending on use

Microbial Monitoring

• Personnel and surface monitoring frequencies vary:– Aseptic processing - after every fill– Other controlled areas - varies from daily to

weekly or less for surfaces – Personnel monitoring often restricted to aseptic

area personnel and personnel working in Class 100 hoods performing tasks such as inoculation

Microbial Monitoring

• Monitoring of surfaces and airborne contaminants during rest periods (following cleaning)– Important for confirming adequacy of cleaning

procedures– Indicates whether HVAC system is operating

properly– NOTE: Disinfectant effectiveness studies also

required for cleaning agents used in the facility

Microbial Monitoring

• Monitoring frequencies and procedures are influenced by a number of factors:– Stage of manufacturing – “Open” or “closed” manufacturing step– Single or multiple product manufacturing

Microbial Monitoring

• Establishment of monitoring locations should be based on performance qualification studies during dynamic conditions– gridding study to determine worst case

locations/most meaningful locations

• Should also establish common flora - will aid in investigations

Setting Alert and Action Limits

• Action limits (for the most part) have been established in a variety of guidance documents

• Alert limits – Lower than action limits – Reflect actual historical results under normal

processing conditions

Exceeding Limits

• Alert limits are designed to provide some warning that environmental quality is approaching action limit and allow you time to correct.

• Exceeding alert limit triggers a warning response - i.e., alert affected area personnel

• Exceeding multiple alerts - triggers action level response

Exceeding Limits

• Action limit excursions require investigations– Speciation of organism(s)– Review batch records from date of excursion– Review other recent EM data (trends)– Review cleaning records– Interview personnel– Product impact - must quarantine until determined

Exceeding Limits

• Excursions from action limits require corrective actions that may include:– More rigorous or additional monitoring– More rigorous cleaning– Retraining of personnel– Procedural changes - change to or addition of

disinfection procedures, for example– HVAC maintenance

Investigations and Corrective Actions

• The investigation procedures to be followed should be pre-established and included in SOPs

• Depending on the outcome of the investigation, corrective actions should be pre-established to the extent possible

• Imperative that EM results be linked to product release so that affected products are not released until investigation completed

• Material Review Board or equivalent should be consulted prior to releasing product that was potentially affected by adverse environmental conditions

Investigations and Corrective Actions

Trending

• Should trend monitoring results (environmental and water) – Periodic (quarterly or monthly) review by QA

and others– Re-evaluation of action and alert limits on an

annual basis– This trending information is generally included

in the Annual Product Review

Temperature and Humidity

• Control of temperature and humidity required for aseptic processing areas – 21 CFR 211.42(c)(10)(ii)

• Generally 65°F and 35-50% humidity are average– Too high - Increases personnel shedding– Too low - Increase static electricity

Temperature and Humidity

• Temperature should be controlled throughout all manufacturing areas

• Temperature and humidity should be monitored and controlled in warehouse areas where temperature/humidity sensitive raw materials are stored– If not able to control humidity, need procedure

to follow if humidity exceeds limit

Water Requirements

Test PotableWater

PurifiedWater

WFI

TOC none 500 ppb 500 ppb

Conduc-tivity

none See USP Table

Micro.Purity

500CFU/ml

100CFU/ml

10 CFU/100 ml

Endo-Toxin

none none 0.25EU/ml

Water For Injection

• Defined by USP

• Water purified by distillation or reverse osmosis

• Prepared from water complying with the U.S. EPA National Primary Drinking Water Regulations

• Contains no added substance

Purified Water

• Defined in USP

• Obtained by a suitable process, usually one of the following:– deionization– reverse osmosis– combination

Potable Water

• Meets National Drinking Water Regulations

• 40 CFR Part 141

• Periodic monitoring in-house as well as periodic certificates from municipality (if applicable)

Water System Monitoring

• WFI Systems– Microbial quality and endotoxin

• Daily system monitoring

• Each use point at least weekly

– TOC and Conductivity• Weekly system monitoring

• can be taken from worst case point (end of loop, return to tank)

Water System Monitoring

• Purified Water Systems– Weekly monitoring of system for:

• microbial quality• TOC • conductivity

Water Use

• WFI – Solvent for preparation of parenteral solutions– Formulation of mammalian cell culture media– Formulation of purification buffers– Final product formulation– Vial and stopper washing – Final rinse for product equipment

Water Use

• Purified Water– Preparation of terminally sterilized

microbiological media– Initial rinsing/cleaning– Laboratory use– Feed for WFI system

Water Use

• Potable Water– Non-product contact uses– Feed for purified water system

Microbial Monitoring Devices

• Slit-to-Agar (STA) - Powered by vacuum, air taken in through a slit below which is a slowly revolving plate.

• Sieve impactor - Vacuum draws in air through perforated cover which is impacted onto petri dish containing nutrient agar

Microbial Monitoring Devices

• Centrifugal Sampler - consists of a propeller that pulls a known volume of air into the unit and then propels the air outward to impact on a nutrient agar strip

• Sterilizable Microbiological Atrium (SMA)- similar to sieve impactor; cover contains uniformly spaced orifices; vacuum draws in air which is impacted on agar plate

Microbial Monitoring Devices

• Surface Air System Sampler - An integrated unit containing an entry section with an agar contact plate; behind is a motor and turbine that pulls air in through the perforated cover and exhausts it beyond the motor.

• Settle plates - qualitative; may be useful in worst case locations

Microbial Monitoring Devices

• Surface contaminant monitoring devices:– Contact Plates - plates filled with nutrient

agar; for regular surfaces– Swabs - useful for hard to reach or irregular

surfaces; swab placed in suitable diluent and inoculated onto microbiological plate

Monitoring Considerations

• Remote sampling probes - validate use of tubing

• Must sample adequate quantity of air to be statistically meaningful.– 80-100 ft3/min

• Must validate growth promotion after exposure of settle plates (or other plates) for prolonged time periods.