[Federal Register Volume 64, Number 159 (Wednesday, August 18, 1999)]
[Notices]
[Pages 44928-44935]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-21352]
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DEPARTMENT OF HEALTH AND HUMAN SERVICES
Food and Drug Administration
[Docket No. 98D-0374]
International Conference on Harmonisation; Guidance on
Specifications: Test Procedures and Acceptance Criteria for
Biotechnological/Biological Products
AGENCY: Food and Drug Administration, HHS.
ACTION: Notice.
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SUMMARY: The Food and Drug Administration (FDA) is publishing a
guidance entitled ``Q6B Specifications: Test Procedures and Acceptance
Criteria for Biotechnological/Biological Products.'' The guidance was
prepared under the auspices of the International Conference on
Harmonisation of Technical Requirements for Registration of
Pharmaceuticals for Human Use (ICH). The guidance provides guidance on
general principles for the selection of test procedures and the setting
and justification of acceptance criteria for biotechnological and
biological products. The guidance is intended to assist in the
establishment of a uniform set of international specifications for
biotechnological and biological products to support new marketing
applications.
DATES: Effective August 18, 1999. Submit written comments at any time.
ADDRESSES: Submit written comments on the guidance to the Dockets
Management Branch (HFA-305), Food and Drug Administration, 5630 Fishers
Lane, rm. 1061, Rockville, MD 20852. Copies of the guidance are
available from the Drug Information Branch (HFD-210), Center for Drug
Evaluation and Research, Food and Drug Administration, 5600 Fishers
Lane, Rockville, MD 20857, 301-827-4573. Single copies of the guidance
may be obtained by mail from the Office of Communication, Training and
Manufacturers Assistance (HFM-40), Center for Biologics Evaluation and
Research (CBER), 1401 Rockville Pike, Rockville, MD 20852, or by
calling the CBER Voice Information System at 1-800-835-4709 or 301-827-
1800. Copies may be obtained from CBER's FAX Information System at 1-
888-CBER-FAX or 301-827-3844.
FOR FURTHER INFORMATION CONTACT:
Neil D. Goldman, Center for Biologics Evaluation and Research (HFM-
20), Food and Drug Administration, 1401 Rockville Pike, Rockville, MD
20852, 301-827-0377.
[[Page 44929]]
Regarding ICH: Janet J. Showalter, Office of Health Affairs (HFY-
20), Food and Drug Administration, 5600 Fishers Lane, Rockville, MD
20857, 301-827-0864.
SUPPLEMENTARY INFORMATION: In recent years, many important initiatives
have been undertaken by regulatory authorities and industry
associations to promote international harmonization of regulatory
requirements. FDA has participated in many meetings designed to enhance
harmonization and is committed to seeking scientifically based
harmonized technical procedures for pharmaceutical development. One of
the goals of harmonization is to identify and then reduce differences
in technical requirements for drug development among regulatory
agencies.
ICH was organized to provide an opportunity for tripartite
harmonization initiatives to be developed with input from both
regulatory and industry representatives. FDA also seeks input from
consumer representatives and others. ICH is concerned with
harmonization of technical requirements for the registration of
pharmaceutical products among three regions: The European Union, Japan,
and the United States. The six ICH sponsors are the European
Commission, the European Federation of Pharmaceutical Industries
Associations, the Japanese Ministry of Health and Welfare, the Japanese
Pharmaceutical Manufacturers Association, the Centers for Drug
Evaluation and Research and Biologics Evaluation and Research, FDA, and
the Pharmaceutical Research and Manufacturers of America. The ICH
Secretariat, which coordinates the preparation of documentation, is
provided by the International Federation of Pharmaceutical
Manufacturers Associations (IFPMA).
The ICH Steering Committee includes representatives from each of
the ICH sponsors and the IFPMA, as well as observers from the World
Health Organization, the Canadian Health Protection Branch, and the
European Free Trade Area.
In the Federal Register of June 9, 1998 (63 FR 31506), FDA
published a draft tripartite guidance entitled ``Q6B Specifications:
Test Procedures and Acceptance Criteria for Biotechnological/Biological
Products.'' The notice gave interested persons an opportunity to submit
comments by July 24, 1998.
After consideration of the comments received and revisions to the
guidance, a final draft of the guidance was submitted to the ICH
Steering Committee and endorsed by the three participating regulatory
agencies on March 11, 1999.
In accordance with FDA's good guidance practices (62 FR 8961,
February 27, 1997), this document has been designated a guidance,
rather than a guideline.
The guidance provides guidance on general principles for the
selection of test procedures and the setting and justification of
acceptance criteria for biotechnological and biological products. The
guidance is intended to assist in the establishment of a uniform set of
international specifications for biotechnological and biological
products to support new marketing applications.
This guidance represents the agency's current thinking on the
selection of test procedures and the setting and justification of
acceptance criteria for biotechnological and biological products. It
does not create or confer any rights for or on any person and does not
operate to bind FDA or the public. An alternative approach may be used
if such approach satisfies the requirements of the applicable statute,
regulations, or both.
As with all of FDA's guidances, the public is encouraged to submit
written comments with new data or other new information pertinent to
this guidance. The comments in the docket will be periodically
reviewed, and, where appropriate, the guidance will be amended. The
public will be notified of any such amendments through a notice in the
Federal Register.
Interested persons may, at any time, submit written comments on the
guidance to the Dockets Management Branch (address above). Two copies
of any comments are to be submitted, except that individuals may submit
one copy. Comments are to be identified with the docket number found in
brackets in the heading of this document. The guidance and received
comments may be seen in the office above between 9 a.m. and 4 p.m.,
Monday through Friday. An electronic version of this guidance is
available on the Internet at ``http://www.fda.gov/cder/guidance/
index.htm'' or at CBER's World Wide Web site at ``http://www.fda.gov/
cber/publications.htm''.
The text of the guidance follows:
Q6B Specifications: Test Procedures and Acceptance Criteria for
Biotechnological/Biological Products\1\
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\1\This guidance represents the agency's current thinking on the
selection of test procedures and the setting and justification of
acceptance criteria for biotechnological and biological products. It
does not create or confer any rights for or on any person and does
not operate to bind FDA or the public. An alternative approach may
be used if such approach satisfies the requirements of the
applicable statute, regulations, or both.
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Table of Contents
1.0 Introduction
1.1 Objective
1.2 Background
1.3 Scope
2.0 Principles for Consideration in Setting Specifications
2.1 Characterization
2.1.1 Physicochemical Properties
2.1.2 Biological Activity
2.1.3 Immunochemical Properties
2.1.4 Purity, Impurities and Contaminants
2.1.5 Quantity
2.2 Analytical Considerations
2.2.1 Reference Standards and Reference Materials
2.2.2 Validation of Analytical Procedures
2.3 Process Controls
2.3.1 Process-Related Considerations
2.3.2 In-process Acceptance Criteria and Action Limits
2.3.3 Raw Materials and Excipient Specifications
2.4 Pharmacopoeial Specifications
2.5 Release Limits versus Shelf-Life Limits
2.6 Statistical Concepts
3.0 Justification of the Specification
4.0 Specifications
4.1 Drug Substance Specification
4.1.1 Appearance and Description
4.1.2 Identity
4.1.3 Purity and Impurities
4.1.4 Potency
4.1.5 Quantity
4.2 Drug Product Specification
4.2.1 Appearance and Description
4.2.2 Identity
4.2.3 Purity and Impurities
4.2.4 Potency
4.2.5 Quantity
4.2.6 General Tests
4.2.7 Additional Testing for Unique Dosage Forms
5.0 Glossary
6.0 Appendices
6.1 Appendix for Physicochemical Characterization
6.1.1 Structural Characterization and Confirmation
6.1.2 Physicochemical Properties
6.2 Appendix for Impurities
6.2.1 Process-Related Impurities and Contaminants
6.2.2 Product-Related Impurities Including Degradation Products
1.0 Introduction
1.1 Objective
This guidance document provides guidance on general principles
for the setting and justification, to the extent possible, of a
uniform set of international specifications for biotechnological and
biological products to support new marketing applications.
1.2 Background
A specification is defined as a list of tests, references to
analytical procedures, and appropriate acceptance criteria which are
numerical limits, ranges, or other criteria for the tests described.
It establishes the set of
[[Page 44930]]
criteria to which a drug substance, drug product, or materials at
other stages of its manufacture should conform to be considered
acceptable for its intended use. ``Conformance to specification''
means that the drug substance and drug product, when tested
according to the listed analytical procedures, will meet the
acceptance criteria. Specifications are critical quality standards
that are proposed and justified by the manufacturer and approved by
regulatory authorities as conditions of approval.
Specifications are one part of a total control strategy designed
to ensure product quality and consistency. Other parts of this
strategy include thorough product characterization during
development, upon which many of the specifications are based,
adherence to good manufacturing practices, a validated manufacturing
process, raw materials testing, in-process testing, stability
testing, etc.
Specifications are chosen to confirm the quality of the drug
substance and drug product rather than to establish full
characterization and should focus on those molecular and biological
characteristics found to be useful in ensuring the safety and
efficacy of the product.
1.3 Scope
The principles adopted and explained in this document apply to
proteins and polypeptides, their derivatives, and products of which
they are components (e.g., conjugates). These proteins and
polypeptides are produced from recombinant or nonrecombinant cell-
culture expression systems and can be highly purified and
characterized using an appropriate set of analytical procedures.
The principles outlined in this document may also apply to other
product types, such as proteins and polypeptides isolated from
tissues and body fluids. To determine applicability, manufacturers
should consult with the appropriate regulatory authorities.
This document does not cover antibiotics, synthetic peptides and
polypeptides, heparins, vitamins, cell metabolites, deoxyribonucleic
acid (DNA) products, allergenic extracts, conventional vaccines,
cells, whole blood, and cellular blood components. A separate ICH
draft guidance, ``Q6A Specifications: Test Procedures and Acceptance
Criteria for New Drug Substances and New Drug Products: Chemical
Substances'' addresses specifications and other criteria for
chemical substances.
This document does not recommend specific test procedures or
specific acceptance criteria, nor does it apply to the regulation of
preclinical and/or clinical research material.
2.0 Principles for Consideration in Setting Specifications
2.1 Characterization
Characterization of a biotechnological or biological product
(which includes the determination of physicochemical properties,
biological activity, immunochemical properties, purity, and
impurities) by appropriate techniques is necessary to allow relevant
specifications to be established. Acceptance criteria should be
established and justified based on data obtained from lots used in
preclinical and/or clinical studies, data from lots used for
demonstration of manufacturing consistency, data from stability
studies, and relevant development data.
Extensive characterization is performed in the development phase
and, where necessary, following significant process changes. At the
time of submission, the product should have been compared with an
appropriate reference standard, if available. When feasible and
relevant, it should be compared with its natural counterpart. Also,
at the time of submission, the manufacturer should have established
appropriately characterized in-house reference materials which will
serve for biological and physicochemical testing of production lots.
New analytical technology and modifications to existing technology
are continually being developed and should be utilized when
appropriate.
2.1.1 Physicochemical properties
A physicochemical characterization program will generally
include a determination of the composition, physical properties, and
primary structure of the desired product. In some cases, information
regarding higher-order structure of the desired product (the
fidelity of which is generally inferred by its biological activity)
may be obtained by appropriate physicochemical methodologies.
An inherent degree of structural heterogeneity occurs in
proteins due to the biosynthetic processes used by living organisms
to produce them; therefore, the desired product can be a mixture of
anticipated post-translationally modified forms (e.g., glycoforms).
These forms may be active and their presence may have no deleterious
effect on the safety and efficacy of the product (section 2.1.4).
The manufacturer should define the pattern of heterogeneity of the
desired product and demonstrate consistency with that of the lots
used in preclinical and clinical studies. If a consistent pattern of
product heterogeneity is demonstrated, an evaluation of the
activity, efficacy, and safety (including immunogenicity) of
individual forms may not be necessary.
Heterogeneity can also be produced during manufacture and/or
storage of the drug substance or drug product. Since the
heterogeneity of these products defines their quality, the degree
and profile of this heterogeneity should be characterized to ensure
lot-to-lot consistency. When these variants of the desired product
have properties comparable to those of the desired product with
respect to activity, efficacy, and safety, they are considered
product-related substances. When process changes and degradation
products result in heterogeneity patterns that differ from those
observed in the material used during preclinical and clinical
development, the significance of these alterations should be
evaluated.
Analytical methods to elucidate physicochemical properties are
listed in appendix 6.1. New analytical technology and modifications
to existing technology are continually being developed and should be
utilized when appropriate.
For the purpose of lot release (section 4), an appropriate
subset of these methods should be selected and justified.
2.1.2 Biological activity
Assessment of the biological properties constitutes an equally
essential step in establishing a complete characterization profile.
An important property is the biological activity that describes the
specific ability or capacity of a product to achieve a defined
biological effect.
A valid biological assay to measure the biological activity
should be provided by the manufacturer. Examples of procedures used
to measure biological activity include:
Animal-based biological assays, which measure an
organism's biological response to the product;
Cell culture-based biological assays, which measure
biochemical or physiological response at the cellular level; and
Biochemical assays, which measure biological
activities such as enzymatic reaction rates or biological responses
induced by immunological interactions.
Other procedures, such as ligand and receptor binding assays,
may be acceptable.
Potency (expressed in units) is the quantitative measure of
biological activity based on the attribute of the product that is
linked to the relevant biological properties, whereas quantity
(expressed in mass) is a physicochemical measure of protein content.
Mimicking the biological activity in the clinical situation is not
always necessary. A correlation between the expected clinical
response and the activity in the biological assay should be
established in pharmacodynamic or clinical studies.
The results of biological assays should be expressed in units of
activity calibrated against an international or national reference
standard, when available and appropriate for the assay utilized.
Where no such reference standard exists, a characterized in-house
reference material should be established and assay results of
production lots reported as in-house units.
Often, for complex molecules, the physicochemical information
may be extensive but unable to confirm the higher-order structure
which, however, can be inferred from the biological activity. In
such cases, a biological assay, with wider confidence limits, may be
acceptable when combined with a specific quantitative measure.
Importantly, a biological assay to measure the biological activity
of the product may be replaced by physicochemical tests only in
those instances where:
Sufficient physicochemical information about the drug,
including higher-order structure, can be thoroughly established by
such physicochemical methods, and relevant correlation to biologic
activity demonstrated; and
There exists a well-established manufacturing history.
Where physicochemical tests alone are used to quantitate the
biological activity (based on appropriate correlation), results
should be expressed in mass.
For the purpose of lot release (section 4), the choice of
relevant quantitative assay (biological and/or physicochemical)
should be justified by the manufacturer.
[[Page 44931]]
2.1.3 Immunochemical properties
When an antibody is the desired product, its immunological
properties should be fully characterized. Binding assays of the
antibody to purified antigens and defined regions of antigens should
be performed, as feasible, to determine affinity, avidity and
immunoreactivity (including cross-reactivity). In addition, the
target molecule bearing the relevant epitope should be biochemically
defined and the epitope itself defined, when feasible.
For some drug substances or drug products, the protein molecule
may need to be examined using immunochemical procedures (e.g.,
enzyme linked immunosorbent assay (ELISA), Western-blot) utilizing
antibodies that recognize different epitopes of the protein
molecule. Immunochemical properties of a protein may serve to
establish its identity, homogeneity, or purity, or serve to quantify
it.
If immunochemical properties constitute lot release criteria,
all relevant information pertaining to the antibody should be made
available.
2.1.4 Purity, impurities, and contaminants
Purity
The determination of absolute, as well as relative, purity
presents considerable analytical challenges, and the results are
highly method dependent. Historically, the relative purity of a
biological product has been expressed in terms of specific activity
(units of biological activity per milligram of product), which is
also highly method dependent. Consequently, the purity of the drug
substance and drug product is assessed by a combination of
analytical procedures.
Due to the unique biosynthetic production process and molecular
characteristics of biotechnological and biological products, the
drug substance can include several molecular entities or variants.
When these molecular entities are derived from anticipated post-
translational modification, they are part of the desired product.
When variants of the desired product are formed during the
manufacturing process and/or storage and have properties comparable
to the desired product, they are considered product-related
substances and not impurities (section 2.1.1).
Individual and/or collective acceptance criteria for product-
related substances should be set, as appropriate.
For the purpose of lot release (section 4), an appropriate
subset of methods should be selected and justified for determination
of purity.
Impurities
In addition to evaluating the purity of the drug substance and
drug product, which may be composed of the desired product and
multiple product-related substances, the manufacturer should also
assess impurities which may be present. Impurities may be either
process- or product-related. They can be of known structure,
partially characterized, or unidentified. When adequate quantities
of impurities can be generated, these materials should be
characterized to the extent possible and, where possible, their
biological activities should be evaluated.
Process-related impurities encompass those that are derived from
the manufacturing process, i.e., cell substrates (e.g., host cell
proteins, host cell DNA), cell culture (e.g., inducers, antibiotics,
or media components), or downstream processing (see appendix,
section 6.2.1). Product-related impurities (e.g., precursors,
certain degradation products) are molecular variants arising during
manufacture and/or storage that do not have properties comparable to
those of the desired product with respect to activity, efficacy, and
safety.
Further, the acceptance criteria for impurities should be based
on data obtained from lots used in preclinical and clinical studies
and manufacturing consistency lots.
Individual and/or collective acceptance criteria for impurities
(product-related and process-related) should be set, as appropriate.
Under certain circumstances, acceptance criteria for selected
impurities may not be necessary (section 2.3).
Examples of analytical procedures that may be employed to test
for the presence of impurities are listed in appendix 6.2. New
analytical technology and modifications to existing technology are
continually being developed and should be utilized when appropriate.
For the purpose of lot release (section 4), an appropriate
subset of these methods should be selected and justified.
Contaminants
Contaminants in a product include all adventitiously introduced
materials not intended to be part of the manufacturing process, such
as chemical and biochemical materials (e.g., microbial proteases)
and/or microbial species. Contaminants should be strictly avoided
and/or suitably controlled with appropriate in-process acceptance
criteria or action limits for drug substance or drug product
specifications (section 2.3). For the special case of adventitious
viral or mycoplasma contamination, the concept of action limits is
not applicable, and the strategies proposed in ICH guidances ``Q5A
Quality of Biotechnological/Biological Products: Viral Safety
Evaluation of Biotechnology Products Derived from Cell Lines of
Human or Animal Origin'' and ``Q5D Quality of Biotechnological/
Biological Products: Derivation and Characterization of Cell
Substrates Used for Production of Biotechnological/Biological
Products'' should be considered.
2.1.5 Quantity
Quantity, usually measured as protein content, is critical for a
biotechnological and biological product and should be determined
using an appropriate assay, usually physicochemical in nature. In
some cases, it may be demonstrated that the quantity values obtained
may be directly related to those found using the biological assay.
When this correlation exists, it may be appropriate to use
measurement of quantity rather than the measurement of biological
activity in manufacturing processes, such as filling.
2.2 Analytical Considerations
2.2.1 Reference standards and reference materials
For drug applications for new molecular entities, it is unlikely
that an international or national standard will be available. At the
time of submission, the manufacturer should have established an
appropriately characterized in-house primary reference material,
prepared from lot(s) representative of production and clinical
materials. In-house working reference material(s) used in the
testing of production lots should be calibrated against this primary
reference material. Where an international or national standard is
available and appropriate, reference materials should be calibrated
against it. While it is desirable to use the same reference material
for both biological assays and physicochemical testing, in some
cases, a separate reference material may be necessary. Also,
distinct reference materials for product-related substances,
product-related impurities, and process-related impurities may need
to be established. When appropriate, a description of the
manufacture and/or purification of reference materials should be
included in the application. Documentation of the characterization,
storage conditions, and formulation supportive of reference
material(s) stability should also be provided.
2.2.2 Validation of analytical procedures
At the time the application is submitted to the regulatory
authorities, applicants should have validated the analytical
procedures used in the specifications in accordance with the ICH
guidances ``Q2A Validation of Analytical Procedures: Definitions and
Terminology'' and ``Q2B Validation of Analytical Procedures:
Methodology,'' except where there are specific issues for unique
tests used for analyzing biotechnological and biological products.
2.3 Process Controls
2.3.1 Process-related considerations
Adequate design of a process and knowledge of its capability are
part of the strategy used to develop a manufacturing process that is
controlled and reproducible, yielding a drug substance or drug
product that meets specifications. In this respect, limits are
justified based on critical information gained from the entire
process spanning the period from early development through
commercial-scale production.
For certain impurities, testing of either the drug substance or
the drug product may not be necessary and may not need to be
included in the specifications if efficient control or removal to
acceptable levels is demonstrated by suitable studies. This testing
can include verification at commercial scale in accordance with
regional regulations. It is recognized that only limited data may be
available at the time of submission of an application. This concept
may, therefore, sometimes be implemented after marketing
authorization, in accordance with regional regulations.
2.3.2 In-process acceptance criteria and action limits
In-process tests are performed at critical decision-making steps
and at other steps where data serve to confirm consistency of the
process during the production of either the drug substance or the
drug product. The results of in-process testing may be recorded as
action limits or reported as acceptance criteria. Performing such
testing may
[[Page 44932]]
eliminate the need for testing of the drug substance or drug product
(section 2.3.1). In-process testing for adventitious agents at the
end of cell culture is an example of testing for which acceptance
criteria should be established.
The use of internal action limits by the manufacturer to assess
the consistency of the process at less critical steps is also
important. Data obtained during development and validation runs
should provide the basis for provisional action limits to be set for
the manufacturing process. These limits, which are the
responsibility of the manufacturer, may be used to initiate
investigation or further action. They should be further refined as
additional manufacturing experience and data are obtained after
product approval.
2.3.3 Raw materials and excipient specifications
The quality of the raw materials used in the production of the
drug substance (or drug product) should meet standards appropriate
for their intended use. Biological raw materials or reagents may
require careful evaluation to establish the presence or absence of
deleterious endogenous or adventitious agents. Procedures that make
use of affinity chromatography (for example, employing monoclonal
antibodies) should be accompanied by appropriate measures to ensure
that such process-related impurities or potential contaminants
arising from their production and use do not compromise the quality
and safety of the drug substance or drug product. Appropriate
information pertaining to the antibody should be made available.
The quality of the excipients used in the drug product
formulation (and in some cases, in the drug substance), as well as
the container/closure systems, should meet pharmacopoeial standards,
where available and appropriate. Otherwise, suitable acceptance
criteria should be established for the nonpharmacopoeial excipients.
2.4 Pharmacopoeial Specifications
Pharmacopoeias contain important requirements pertaining to
certain analytical procedures and acceptance criteria which, where
relevant, are part of the evaluation of either the drug substance or
drug product. Such monographs, applicable to biotechnological and
biological products, generally include, but are not limited to,
tests for sterility, endotoxins, microbial limits, volume in
container, uniformity of dosage units, and particulate matter. With
respect to the use of pharmacopoeial methods and acceptance
criteria, the value of this guidance is linked to the extent of
harmonization of the analytical procedures of the pharmacopoeias.
The pharmacopoeias are committed to developing identical or
methodologically equivalent test procedures and acceptance criteria.
2.5 Release Limits Versus Shelf-Life Limits
The concept of release limits versus shelf-life limits may be
applied where justified. This concept pertains to the establishment
of limits which are tighter for the release than for the shelf-life
of the drug substance or drug product. Examples where this may be
applicable include potency and degradation products. In some
regions, the concept of release limits may only be applicable to in-
house limits and not to the regulatory shelf-life limits.
2.6 Statistical Concepts
Appropriate statistical analysis should be applied, when
necessary, to quantitative data reported. The methods of analysis,
including justification and rationale, should be described fully.
These descriptions should be sufficiently clear to permit
independent calculation of the results presented.
3.0 Justification of the Specification
The setting of specifications for drug substance and drug
product is part of an overall control strategy which includes
control of raw materials and excipients, in-process testing, process
evaluation or validation, adherence to good manufacturing practices,
stability testing, and testing for consistency of lots. When
combined in total, these elements provide assurance that the
appropriate quality of the product will be maintained. Since
specifications are chosen to confirm the quality rather than to
characterize the product, the manufacturer should provide the
rationale and justification for including and/or excluding testing
for specific quality attributes. The following points should be
taken into consideration when establishing scientifically
justifiable specifications.
Specifications are linked to a manufacturing process.
Specifications should be based on data obtained from lots used
to demonstrate manufacturing consistency. Linking specifications to
a manufacturing process is important, especially for product-related
substances, product-related impurities, and process-related
impurities. Process changes and degradation products produced during
storage may result in heterogeneity patterns which differ from those
observed in the material used during preclinical and clinical
development. The significance of these alterations should be
evaluated.
Specifications should account for the stability of
drug substance and drug product.
Degradation of drug substance and drug product, which may occur
during storage, should be considered when establishing
specifications. Due to the inherent complexity of these products,
there is no single stability-indicating assay or parameter that
profiles the stability characteristics. Consequently, the
manufacturer should propose a stability-indicating profile. The
result of this stability-indicating profile will then provide
assurance that changes in the quality of the product will be
detected. The determination of which tests should be included will
be product specific. The manufacturer is referred to the ICH
guidance ``Q5C Stability Testing of Biotechnological/Biological
Products.''
Specifications are linked to preclinical and clinical
studies.
Specifications should be based on data obtained for lots used in
preclinical and clinical studies. The quality of the material made
at commercial scale should be representative of the lots used in
preclinical and clinical studies.
Specifications are linked to analytical procedures.
Critical quality attributes may include items such as potency,
the nature and quantity of product-related substances, product-
related impurities, and process-related impurities. Such attributes
can be assessed by multiple analytical procedures, each yielding
different results. In the course of product development, it is not
unusual for the analytical technology to evolve in parallel with the
product. Therefore, it is important to confirm that data generated
during development correlate with those generated at the time the
marketing application is filed.
4.0 Specifications
Selection of tests to be included in the specifications is
product specific. The rationale used to establish the acceptable
range of acceptance criteria should be described. Acceptance
criteria should be established and justified based on data obtained
from lots used in preclinical and/or clinical studies, data from
lots used for demonstration of manufacturing consistency, data from
stability studies, and relevant development data.
In some cases, testing at production stages rather than testing
at the finished drug substance or drug product stages may be
appropriate and acceptable. In such circumstances, test results
should be considered as in-process acceptance criteria and included
in the specification of drug substance or drug product in accordance
with the requirements of the regional regulatory authorities.
4.1 Drug Substance Specification
Generally, the following tests and acceptance criteria are
considered applicable to all drug substances (for analytical
procedures, see section 2.2.2). Pharmacopoeial tests (e.g.,
endotoxin detection) should be performed on the drug substance,
where appropriate. Additional drug substance specific acceptance
criteria may also be necessary.
4.1.1 Appearance and description
A qualitative statement describing the physical state (e.g.,
solid, liquid) and color of a drug substance should be provided.
4.1.2 Identity
The identity test(s) should be highly specific for the drug
substance and should be based on unique aspects of its molecular
structure and/or other specific properties. More than one test
(physicochemical, biological, and/or immunochemical) may be
necessary to establish identity. The identity test(s) can be
qualitative in nature. Some of the methods typically used for
characterization of the product as described in section 2.1 and in
appendix 6.1 may be employed and/or modified as appropriate for the
purpose of establishing identity.
4.1.3 Purity and impurities
The absolute purity of biotechnological and biological products
is difficult to determine and the results are method dependent
(section 2.1.4). Consequently, the purity of the drug substance is
usually estimated by a combination of methods. The
[[Page 44933]]
choice and optimization of analytical procedures should focus on the
separation of the desired product from product-related substances
and from impurities.
The impurities observed in these products are classified as
process-related and product-related:
Process-related impurities (section 2.1.4) in the
drug substance may include cell culture media, host cell proteins,
DNA, monoclonal antibodies or chromatographic media used in
purification, solvents, and buffer components. These impurities
should be minimized by the use of appropriate, well-controlled
manufacturing processes.
Product-related impurities (section 2.1.4) in the drug
substance are molecular variants with properties different from
those of the desired product formed during manufacture and/or
storage.
For the impurities, the choice and optimization of analytical
procedures should focus on the separation of the desired product and
product-related substances from impurities. Individual and/or
collective acceptance criteria for impurities should be set, as
appropriate. Under certain circumstances, acceptance criteria for
selected impurities may not be necessary (section 2.3).
4.1.4 Potency
A relevant, validated potency assay (section 2.1.2) should be
part of the specifications for a biotechnological or biological drug
substance and/or drug product. When an appropriate potency assay is
used for the drug product (section 4.2.4), an alternative method
(physicochemical and/or biological) may suffice for quantitative
assessment at the drug substance stage. In some cases, the
measurement of specific activity may provide additional useful
information.
4.1.5 Quantity
The quantity of the drug substance, usually based on protein
content (mass), should be determined using an appropriate assay. The
quantity determination may be independent of a reference standard or
material. In cases where product manufacture is based upon potency,
there may be no need for an alternate determination of quantity.
4.2 Drug Product Specification
Generally, the following tests and acceptance criteria are
considered applicable to all drug products. Each section (4.2.1-
4.2.5) is cross-referenced to respective sections (4.1.1-4.1.5)
under Drug Substance Specification. Pharmacopoeial requirements
apply to the relevant dosage forms. Typical tests found in the
pharmacopoeia include, but are not limited to, sterility, endotoxin,
microbial limits, volume in container, particulate matter,
uniformity of dosage units, and moisture content for lyophilized
drug products. If appropriate, testing for uniformity of dosage
units may be performed as in-process controls, and corresponding
acceptance criteria are set.
4.2.1 Appearance and description
A qualitative statement describing the physical state (e.g.,
solid, liquid), color, and clarity of the drug product should be
provided.
4.2.2 Identity
The identity test(s) should be highly specific for the drug
product and should be based on unique aspects of its molecular
structure and other specific properties. The identity test(s) can be
qualitative in nature. While it is recognized that in most cases a
single test is adequate, more than one test (physicochemical,
biological, and/or immunochemical) may be necessary to establish
identity for some products. Some of the methods typically used for
characterization of the product as described in section 2.1 and in
appendix 6.1 may be employed and/or modified as appropriate for the
purpose of establishing identity.
4.2.3 Purity and impurities
Impurities may be generated or increased during manufacture and/
or storage of the drug product. These may be either the same as
those occurring in the drug substance itself, process-related, or
degradation products which form specifically in the drug product
during formulation or during storage. If impurities are
qualitatively and quantitatively (i.e., relative amounts and/or
concentrations) the same as in the drug substance, testing is not
considered necessary. If impurities are known to be introduced or
formed during the production and/or storage of the drug product, the
levels of these impurities should be determined and acceptance
criteria established.
Acceptance criteria and analytical procedures should be
developed and justified, based upon previous experience with the
drug product, to measure changes in the drug substance during the
manufacture and/or storage of the drug product.
The choice and optimization of analytical procedures should
focus on the separation of the desired product and product-related
substances from impurities including degradation products, and from
excipients.
4.2.4 Potency
A relevant, validated potency assay (section 2.1.2) should be
part of the specifications for a biotechnological and biological
drug substance and/or drug product. When an appropriate potency
assay is used for the drug substance, an alternative method
(physicochemical and/or biological) may suffice for quantitative
assessment of the drug product. However, the rationale for such a
choice should be provided.
4.2.5 Quantity
The quantity of the drug substance in the drug product, usually
based on protein content (mass), should be determined using an
appropriate assay. In cases where product manufacture is based upon
potency, there may be no need for an alternate determination of
quantity.
4.2.6 General tests
Physical description and the measurement of other quality
attributes are often important for the evaluation of the drug
product functions. Examples of such tests include pH and osmolarity.
4.2.7 Additional testing for unique dosage forms
It should be recognized that certain unique dosage forms may
need additional tests other than those mentioned above.
5.0 Glossary
Acceptance criteria: Numerical limits, ranges, or other suitable
measures for acceptance of the results of analytical procedures
which the drug substance or drug product or materials at other
stages of manufacture should meet.
Action limit: An internal (in-house) value used to assess the
consistency of the process at less critical steps.
Biological activity: The specific ability or capacity of the
product to achieve a defined biological effect. Potency is the
quantitative measure of the biological activity.
Contaminants: Any adventitiously introduced materials (e.g.,
chemical, biochemical, or microbial species) not intended to be part
of the manufacturing process of the drug substance or drug product.
Degradation products: Molecular variants resulting from changes
in the desired product or product-related substances brought about
over time and/or by the action of, e.g., light, temperature, pH,
water, or by reaction with an excipient and/or the immediate
container/closure system. Such changes may occur as a result of
manufacture and/or storage (e.g., deamidation, oxidation,
aggregation, proteolysis). Degradation products may be either
product-related substances or product-related impurities.
Desired Product: (1) The protein that has the expected
structure, or (2) the protein that is expected from the DNA sequence
and anticipated post-translational modification (including
glycoforms), and from the intended downstream modification to
produce an active biological molecule.
Drug product (Dosage form; Finished product): A pharmaceutical
product type that contains a drug substance, generally in
association with excipients.
Drug substance (Bulk material): The material that is
subsequently formulated with excipients to produce the drug product.
It can be composed of the desired product, product-related
substances, and product- and process-related impurities. It may also
contain excipients including other components, such as buffers.
Excipient: An ingredient added intentionally to the drug
substance which should not have pharmacological properties in the
quantity used.
Impurity: Any component present in the drug substance or drug
product that is not the desired product, a product-related
substance, or an excipient including buffer components. It may be
either process- or product-related.
In-house primary reference material: An appropriately
characterized material prepared by the manufacturer from a
representative lot(s) for the purpose of biological assay and
physicochemical testing of subsequent lots, and against which in-
house working reference material is calibrated.
In-house working reference material: A material prepared
similarly to the primary
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reference material that is established solely to assess and control
subsequent lots for the individual attribute in question. It is
always calibrated against the in-house primary reference material.
Potency: The measure of the biological activity using a suitably
quantitative biological assay (also called potency assay or
bioassay), based on the attribute of the product which is linked to
the relevant biological properties.
Process-related impurities: Impurities that are derived from the
manufacturing process. They may be derived from cell substrates
(e.g., host cell proteins, host cell DNA), cell culture (e.g.,
inducers, antibiotics, or media components), or downstream
processing (e.g., processing reagents or column leachables).
Product-related impurities: Molecular variants of the desired
product (e.g., precursors, certain degradation products arising
during manufacture and/or storage) which do not have properties
comparable to those of the desired product with respect to activity,
efficacy, and safety.
Product-related substances: Molecular variants of the desired
product formed during manufacture and/or storage which are active
and have no deleterious effect on the safety and efficacy of the
drug product. These variants possess properties comparable to the
desired product and are not considered impurities.
Reference standards: International or national standards.
Specification: A list of tests, references to analytical
procedures, and appropriate acceptance criteria which are numerical
limits, ranges, or other criteria for the tests described. It
establishes the set of criteria to which a drug substance, drug
product, or materials at other stages of its manufacture should
conform to be considered acceptable for its intended use.
``Conformance to specification'' means that the drug substance and
drug product, when tested according to the listed analytical
procedures, will meet the acceptance criteria. Specifications are
critical quality standards that are proposed and justified by the
manufacturer and approved by regulatory authorities as conditions of
approval.
6.0 Appendices
6.1 Appendix for Physiochemical Characterization
This appendix provides examples of technical approaches that
might be considered for structural characterization and
confirmation, and evaluation of physicochemical properties of the
desired product, drug substance, and/or drug product. The specific
technical approach employed will vary from product to product, and
alternative approaches, other than those included in this appendix,
will be appropriate in many cases. New analytical technology and
modifications to existing technology are continuously being
developed and should be utilized when appropriate.
6.1.1 Structural characterization and confirmation
(a) Amino acid sequence
The amino acid sequence of the desired product should be
determined to the extent possible using approaches such as those
described in items (b) through (e) and then compared with the
sequence of the amino acids deduced from the gene sequence of the
desired product.
(b) Amino acid composition
The overall amino acid composition is determined using various
hydrolytic and analytical procedures and compared with the amino
acid composition deduced from the gene sequence for the desired
product, or the natural counterpart, if considered necessary. In
many cases, amino acid composition analysis provides some useful
structural information for peptides and small proteins, but such
data are generally less definitive for large proteins. Quantitative
amino acid analysis data can also be used to determine protein
content in many cases.
(c) Terminal amino acid sequence
Terminal amino acid analysis is performed to identify the nature
and homogeneity of the amino- and carboxy-terminal amino acids. If
the desired product is found to be heterogeneous with respect to the
terminal amino acids, the relative amounts of the variant forms
should be determined using an appropriate analytical procedure. The
sequence of these terminal amino acids should be compared with the
terminal amino acid sequence deduced from the gene sequence of the
desired product.
(d) Peptide map
Selective fragmentation of the product into discrete peptides is
performed using suitable enzymes or chemicals, and the resulting
peptide fragments are analyzed by high pressure liquid
chromatography (HPLC) or other appropriate analytical procedures.
The peptide fragments should be identified to the extent possible
using techniques such as amino acid compositional analysis, N-
terminal sequencing, or mass spectrometry. Peptide mapping of the
drug substance or drug product using an appropriately validated
procedure is a method that is frequently used to confirm desired
product structure for lot release purposes.
(e) Sulfhydryl group(s) and disulfide bridges
If, based on the gene sequence for the desired product, cysteine
residues are expected, the number and positions of any free
sulfhydryl groups and/or disulfide bridges should be determined, to
the extent possible. Peptide mapping (under reducing and nonreducing
conditions), mass spectrometry, or other appropriate techniques may
be useful for this evaluation.
(f) Carbohydrate structure
For glycoproteins, the carbohydrate content (neutral sugars,
amino sugars, and sialic acids) is determined. In addition, the
structure of the carbohydrate chains, the oligosaccharide pattern
(antennary profile), and the glycosylation site(s) of the
polypeptide chain are analyzed, to the extent possible.
6.1.2 Physicochemical properties
(a) Molecular weight or size
Molecular weight (or size) is determined using size exclusion
chromatography, sodium dodecyl sulfate (SDS)-polyacrylamide gel
electrophoresis (under reducing and/or nonreducing conditions), mass
spectrometry, and other appropriate techniques.
(b) Isoform pattern
This is determined by isoelectric focusing or other appropriate
techniques.
(c) Extinction coefficient (or molar absorptivity)
In many cases, it will be desirable to determine the extinction
coefficient (or molar absorptivity) for the desired product at a
particular ultraviolet (UV)/visible wavelength (e.g., 280
nanometers). The extinction coefficient is determined using UV/
visible spectrophotometry on a solution of the product having a
known protein content as determined by techniques such as amino acid
compositional analysis or nitrogen determination. If UV absorption
is used to measure protein content, the extinction coefficient for
the particular product should be used.
(d) Electrophoretic patterns
Electrophoretic patterns and data on identity, homogeneity, and
purity can be obtained by polyacrylamide gel electrophoresis,
isoelectric focusing, SDS-polyacrylamide gel electrophoresis,
Western-blot, capillary electrophoresis, or other suitable
procedures.
(e) Liquid chromatographic patterns
Chromatographic patterns and data on the identity, homogeneity,
and purity can be obtained by size exclusion chromatography,
reverse-phase liquid chromatography, ion-exchange liquid
chromatography, affinity chromatography, or other suitable
procedures.
(f) Spectroscopic profiles
The UV and visible absorption spectra are determined as
appropriate. The higher-order structure of the product is examined
using procedures such as circular dichroism, nuclear magnetic
resonance (NMR), or other suitable techniques as appropriate.
6.2 Appendix for Impurities
This appendix lists potential impurities, their sources, and
examples of relevant analytical approaches for detection. Specific
impurities and technical approaches employed, as in the case of
physicochemical characterization, will vary from product to product,
and alternative approaches other than those listed in this appendix
will be appropriate in many cases. New analytical technology and
modifications to existing technology are continuously being
developed and should be applied when appropriate.
6.2.1 Process-related impurities and contaminants
These are derived from the manufacturing process (section 2.1.4)
and are classified into three major categories: Cell substrate-
derived, cell culture-derived and downstream-derived.
(a) Cell substrate-derived impurities include, but are not
limited to, proteins derived from the host organism and nucleic acid
(host cell genomic, vector, or total DNA). For host cell proteins, a
sensitive assay, e.g., immunoassay, capable of detecting a wide
range of protein impurities is generally utilized. In the case of an
immunoassay, a polyclonal antibody used in the test is generated by
immunization with a preparation of a production cell minus the
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product-coding gene, fusion partners, or other appropriate cell
lines. The level of DNA from the host cells can be detected by
direct analysis on the product (such as hybridization techniques).
Clearance studies, which could include spiking experiments at the
laboratory scale, to demonstrate the removal of cell substrate-
derived impurities such as nucleic acids and host cell proteins may
sometimes be used to eliminate the need for establishing acceptance
criteria for these impurities.
(b) Cell culture-derived impurities include, but are not limited
to, inducers, antibiotics, serum, and other media components.
(c) Downstream-derived impurities include, but are not limited
to, enzymes, chemical and biochemical processing reagents (e.g.,
cyanogen bromide, guanidine, oxidizing and reducing agents),
inorganic salts (e.g., heavy metals, arsenic, nonmetallic ion),
solvents, carriers, ligands (e.g., monoclonal antibodies), and other
leachables.
For intentionally introduced, endogenous, and adventitious
viruses, the ability of the manufacturing process to remove and/or
inactivate viruses should be demonstrated as described in ICH
guidance ``Q5A Viral Safety Evaluation of Biotechnology Products
Derived From Cell Lines of Human or Animal Origin.''
6.2.2 Product-related impurities including degradation products
The following represents the most frequently encountered
molecular variants of the desired product and lists relevant
technology for their assessment. Such variants may need considerable
effort in isolation and characterization in order to identify the
type of modification(s). Degradation products arising in significant
amounts during manufacture and/or storage should be tested for and
monitored against appropriately established acceptance criteria.
(a) Truncated forms. Hydrolytic enzymes or chemicals may
catalyze the cleavage of peptide bonds. These may be detected by
HPLC or SDS-PAGE. Peptide mapping may be useful, depending on the
property of the variant.
(b) Other modified forms. Deamidated, isomerized, mismatched S-S
linked, oxidized, or altered conjugated forms (e.g., glycosylation,
phosphorylation) may be detected and characterized by
chromatographic, electrophoretic, and/or other relevant analytical
methods (e.g., HPLC, capillary electrophoresis, mass spectroscopy,
circular dichroism).
(c) Aggregates. The category of aggregates includes dimers and
higher multiples of the desired product. These are generally
resolved from the desired product and product-related substances and
quantitated by appropriate analytical procedures (e.g., size
exclusion chromatography, capillary electrophoresis).
Dated: August 11, 1999.
Margaret M. Dotzel,
Acting Associate Commissioner for Policy.
[FR Doc. 99-21352 Filed 8-17-99; 8:45 am]
BILLING CODE 4160-01-F