1. Purpose
The purpose of this Guideline is to provide guidance on the manufacture and microbiological testing of sterile Investigational Medicinal Products (IMP) and Active Pharmaceutical Ingredients (API).
2. Scope and Applicability
The guideline applies to the manufacture of sterile products within R&D for human use and for stability studies intended to be filed with regulatory submissions. The guideline applies to aseptically processed as well as terminally sterilized products. The provisions of this guideline additionally apply to contractors manufacturing sterile product for R&D. In the context of this guideline ‘product’ includes sterile API and formulated IMP. The guideline scope excludes pre-clinical materials. The guideline also does not include biological products and Active Pharmaceutical Ingredients produced by cell culture/fermentation, which will be covered in a separate guideline
3. Definitions
3.1 Active Pharmaceutical Ingredient (API)
Any substance or mixture of substances intended to be used in the manufacture of a drug (medicinal) product that when used in the production of a drug becomes an active ingredient of the drug product. Such substances are intended to furnish pharmacological activity or other direct effect in the diagnosis, cure, mitigation, treatment or prevention of disease or to affect the structure and function of the body.
3.2 Investigational Medicinal Product (IMP)
A pharmaceutical form of an active ingredient or placebo being tested or used as a reference in a Clinical Study, including a product with a marketing authorization when used or assembled (formulated or packaged) in a way different from the approved form, or when used for an unapproved indication, or when used to gain further information about an approved use.
3.3 Clean Area
An area with defined environmental control of particulate and microbial contamination constructed and used in such a way as to reduce the introduction, generation and retention of contaminants within the area (Eudralex definition).
3.4 Controlled Area
An area where unspecialized product, in-process materials, and containers/closures are prepared (FDA definition).
3.5 Critical Area
An area in which the sterilized dosage form, containers, and closures are exposed to the environment (FDA definition).
3.6 Grade A
Zone of local protection for high risk operations such as the filling of open containers, operations involving exposed primary packaging materials and the making of aseptic connections. Normally provided by laminar air flow work station. Generally corresponds to US/FDA Class 100 at rest and in operation. Note: “At rest” conditions are with HVAC in operation, equipment off manufacturing personnel not working. “In operation” conditions are with equipment on and personnel at work.
3.7 Grade B
Background environment for a grade A zone used for aseptic preparation and filling operations. Generally corresponds to US/FDA Class 100 at rest and Class 10,000 in operation.
3.8 Grade C
Classification used for carrying out the less critical stages of sterile product manufacture. Also used as the background area for the preparation of solutions and components and as the background for filling of terminally sterilized products. Generally corresponds to US/FDA Class 10,000 at rest and Class 100,000 in operation.
3.9 Grade D
A classification used for carrying out the least critical stages of sterile product manufacture. A minimum standard, for example, for areas used for the manufacture of sterile products where solutions and packaging or other components are prepared, stored or handled or otherwise processed after the commencement of manufacture. Generally corresponds to US/FDA Class 100,000 at rest.
4. Responsibilities
4.1 R&D Line Management
The management of R&D at the site are responsible for ensuring that appropriate procedures for sterile manufacturing and testing are in place at sites where sterile manufacturing will occur, and that sufficient training is conducted.
4.2 R&D Quality Management
R&D QA management is responsible for ensuring that the quality systems described in this guideline are established and monitored.
5. Guideline
5.1 General
The manufacture of sterile products (Investigational Medicinal Products and Active Pharmaceutical Ingredients for the purposes of this Guideline) requires facilities that are suitably designed and qualified. Design features alone do not assure the quality of sterile products, especially those prepared aseptically, which additionally relies to a large part upon robust processes and procedures, and the training and experience of personnel. Process qualification, taking into account related items such as operator gowning, sterile filtration, environmental controls, etc., is essential for sterile products manufacture.
Specific consideration should be given depending on the type of process (e.g., aseptic processing, isolator, or blow/fill/seal technology).
Facility design philosophies, air classifications, environmental monitoring limits and other operational requirements are specified in Annex 1 of ‘The Rules Governing Medicinal Products in the European Union” and the FDA “Guideline on Sterile Drug Products Produced by Aseptic Processing”. Additional guidance regarding specific engineering for facilities used in the manufacture of sterile products is to be found in the ISPE Baseline Pharmaceutical Engineering Guide Volume 3.
The ICH Good Manufacturing Practice Guide for Active Pharmaceutical Ingredients indicates that applicable GMP guidelines for drug products, which are reflected in this guideline, generally would apply to the manufacture of sterile API.
The following guidance is provided only as a summary of requirements defined in the various regulations and technical papers on sterile manufacturing, and gives some additional points of clarification. The reference section includes a list of documents, which include detailed information on each of the areas discussed below and these should be consulted for more detailed guidance.
5.2 Sterilization Processes
Aseptic processing of sterile products must only be employed when terminal sterilization in the final container is not possible. All product sterilization processes must be validated. All process validation including sterilization of equipment, utensils, containers and closures must be completed before material for clinical trials can be manufactured.
Specific requirements for the periodic re-qualification of sterilization processes must be in place. Fixed loading patterns and cycles must be established for processes performing batch sterilization of product, components, and equipment. Sterilized items must be readily identifiable to avoid mix up with un-sterilized items.
Cycle charts for sterilization processes must be reviewed and approved to ensure compliance of each cycle with validated process parameters. Post, and where possible, pre-filtration testing of product sterilizing filters must be performed to ensures the integrity of each batch.
For aseptic processing, a second sterilizing filter immediately prior to filling is recommended. Where biological indicators are used (eg in validation studies), controls to avoid contamination of the facility and product must be used. Time limits between critical processing steps must be defined (e.g., between equipment sterilization/depyrogenisation and use).
Specific requirements for inspection of sterile investigational medicinal products must be described in written procedures.
5.3 Buildings, Facilities and Equipment
Manufacture must take place within clean areas. Four grades of clean areas are defined by the European regulations (Grades A, B, C and D), and three classes are defined in the US (class 100; 10,000; and 100,000). For particle counts, the EU Grades generally correspond to the US classifications. Particle counts in different grades, at rest and in operations, are given in Appendix A.
There are important differences between the two sets of classifications (European and US classifications), and these should be understood at facilities producing sterile product for both the European and US markets. The ISPE Baseline Guide for Sterile Manufacturing Facilities includes a good overview of the differences between the US and EU classifications.
General requirements for buildings, facilities and equipment include the following: Clean areas must be classified, and use HEPA filtered air.
In critical areas, there must be HEPA filtered, unidirectional airflow over sterile product, containers, and closures. HEPA filter leak testing must be performed at least twice a year in critical areas. There must be pressure differentials between clean areas. Facilities must be operated according to defined procedures consistent with minimizing microbiological and extraneous contamination during all stages of processing, including pre- and post sterilization.
The transfer of equipment, components, fluids and gases to critical areas must be according to approved procedures and validated processes. There must be no sinks in critical areas.
Entry of personnel, equipment and materials into critical areas for the manufacture of sterile product must be through airlocks. Airlocks must have interlocking doors or alarms. The final stage of entry to critical areas must be of the same grade (at rest) as the area to which it leads.
Separate change rooms for entry/exit are desirable. Conveyor belts must not pass from a higher classified area to a lower classified area unless continuously sterilized. Equipment design should provide for maintenance outside clean areas. Lyophilizer chambers must be sterilizable.
5.3.1 Sanitization and Cleaning
Sanitization and cleaning programs must be in place and described in sufficient detail to ensure clean, sanitary and sterile (where appropriate) conditions. Equipment surfaces contacting sterile drug product or sterile and closures must be sterilized prior to each use. Validated equipment sterilization process must be used, with storage time limits.
Written procedures for the use of pest control, sanitizing and cleaning agents must include provisions to prevent contamination of equipment, materials and product The efficacy of sanitizing agents must be qualified. More than one type of sanitizing agent must be employed on a rotating basis, and the efficacy of the sanitizing agent should be assured over time. Sanitizing agents used in critical areas must be sterilized before use.
5.3.2 Environmental Monitoring
Environmental monitoring programs for viable organisms must be defined, and include monitoring types, locations, and frequencies. Environmental monitoring programs for non-viable particles must be defined including locations and frequencies.
Facility monitoring programs, including temperature, humidity and pressure differentials must be in place. Environmental monitoring programs must include alert and action limits, defined responses to excursions, and periodic trends of monitoring results. Alert limits must reflect the limit of normal operating conditions in order to highlight possible shifts in conditions, and must be based on historical data where there is sufficient data to do this.
5.3.3 Personnel
Clothing worn by operators, cleaning personnel, and support personnel must be appropriate for the operations carried out within each area of classification.
There must be documented control over garment sterilization and use for critical areas. For operations carried out in critical areas, the use of face protection that minimizes the area of exposed skin must be adopted. Operators must undergo assessment of gowning competence both initially (before working in a critical area) and also at periodic re-qualifications. Operator gowning qualification for sterile operations must include microbiological assessments.
Regular training, specific to the sterile manufacturing operations being performed, must be conducted, and include personnel health and hygiene awareness. Maximum occupancy limits for classified areas must be defined and qualified through Process Simulation Trials (see section 6.2).
5.3.4 Components and Materials
Components (e.g., primary containers and closures) and ingredients (including water) used in manufacture of sterile products must be handled and stored in a controlled manner to ensure traceability of identity and status, and to avoid cross contamination. The movement and in-process storage of materials and product must be controlled to prevent contamination.
For starting materials to be used in EU potential products, all containers of a given batch must be sampled and tested to confirm identity. For the US, a sample is required only for each lot in each shipment from the supplier. Storage, handling and testing of raw materials must be conducted in a manner consistent with good microbiological control. Procedures must be defined for the bioburden and/or any other relevant microbiological testing (endotoxin) of raw materials. Following washing of components, procedures must ensure that they are protected from recontamination.
Initial rinse must be with purified water. Final washing rinses must be with WFI. The time between washing and sterilizing of components must be minimized. Overkill sterilization of components must be employed. Containers and closures must be cleaned, sterilized and depyrogenated by validated processes.
Detergents for cleaning must be avoided where possible. Component processing must be done in a manner to reduce the potential for particulate contamination, including the use of filtered water. There must be procedures for cleaning broken containers from processing equipment. Container/closure integrity for sterile products must be qualified.
5.4 Process Simulation
Trials Process Simulation Trials (PST) are also referred to as Sterile Media fills, Broth trials, or Media fills. Requirements for the validation of aseptic sterile processing, including process simulation trials are indicated in technical monographs. Written procedures are required indicating how these requirements are enacted, and should address the following: Justification must be provided where process simulations of development processes are allowable using a filling run of less than 3000 containers (eg small batch sizes), or where a PST matrix approach may be used to support the filling of a range of container sizes. All anticipated process interventions must be defined and simulated during PSTs.
All processing steps, including those performed post-sterilization, must be used. Process simulations, once complete, must be fully incubated and assessed. Circumstances under which a PST, once commenced, may or may not be terminated (i.e. PST cancellation policy) must be in place.
Circumstances under which a satisfactorily filled unit can or cannot be discarded (i.e. container discard policy) must be described in procedures. Normally only containers identified as broken must be excluded from incubation after filling.
All units which have been satisfactorily filled and closed must be incubated. ‘In-process’ checks must be simulated where appropriate, but filled containers must generally not be discarded unless they were not satisfactorily filled and closed. It may be beneficial to have trained observers who are independent from the production team monitor the PST, or portion of it.
Written observations may be helpful in routinely providing feedback to operators in terms of good or poor aseptic techniques, or otherwise may provide valuable in the event of a PST failure. Consideration should be given to overlaying filled containers with compressed air rather than Nitrogen to avoid the production of anaerobic conditions preventing microbiological growth in a contaminated container. Any contaminated unit must be investigated.
5.5 Sterility Testing
Specific guidance for microbiological laboratories is given in the FDA ‘Guideline on Sterile Drug Products Produced by Aseptic Processing’. Collection of batch samples for sterility testing must follow established sampling plans to ensure that the containers chosen are representative of the critical parts of the process or sterilizer load. The microbiological testing laboratory environment for sterility testing of aseptically manufactured products must employ facilities, controls and monitoring comparable to those used for filling/closing operations.