[Federal Register Volume 63, Number 110 (Tuesday, June 9, 1998)]
[Notices]
[Pages 31506-31513]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-15193]
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DEPARTMENT OF HEALTH AND HUMAN SERVICES
Food and Drug Administration
[Docket No. 98D-0374]
International Conference on Harmonisation; Draft Guidance on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SUMMARY: The Food and Drug Administration (FDA) is publishing a draft
guidance entitled ``Q6B Specifications: Test Procedures and Acceptance
Criteria for Biotechnological/Biological Products.'' The draft guidance
was prepared under the auspices of the International Conference on
Harmonisation of Technical Requirements for Registration of
Pharmaceuticals for Human Use (ICH). The draft guidance provides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 The draft guidance is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: Written comments by July 24, 1998.
ADDRESSES: Submit written comments on the draft guidance to the Dockets
Management Branch (HFA-305), Food and Drug Administration, 12420
Parklawn Dr., rm. 1-23, Rockville, MD 20857. Copies of the draft
guidance are available from the Drug Information Branch (HFD-210),
Center for Drug
[[Page 31507]]
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), 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:
Regarding the guidance: Neil D. Goldman, Center for Biologics
Evaluation and Research (HFM-20), Food and Drug Administration, 1401
Rockville Pike, Rockville, MD 20852, 301-827-0377.
Regarding the 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 February 1998, the ICH Steering Committee agreed that a draft
guidance entitled ``Q6B Specifications: Test Procedures and Acceptance
Criteria for Biotechnological/Biological Products'' should be made
available for public comment. The draft guidance is the product of the
Quality Expert Working Group of the ICH. Comments about this draft will
be considered by FDA and the Quality Expert Working Group.
The draft 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
draft 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 draft guidance represents the agency's current thinking on the
selection of test procedures and the setting and justification of
acceptance criteria for biotechnological/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.
Interested persons may, on or before July 24, 1998, submit to the
Dockets Management Branch (address above) written comments on the draft
guidance. 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
draft 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 draft 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 draft guidance follows:
Q6B Specifications: Test Procedures and Acceptance Criteria for
Biotechnological/Biological Products \1\
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\1\ This draft guidance represents the agency's current thinking
on the selection of test procedures and the setting and
justification of acceptance criteria for biotechnological/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 Scope
2.0 General 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/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/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/Confirmation
6.1.2 Physicochemical Properties
6.2 Appendix for Impurities
6.2.1 Process-Related Impurities
6.2.2 Product-Related Impurities
1.0 Introduction
A specification is defined as a list of tests, references to
analytical procedures, and appropriate acceptance criteria with
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 their manufacture should
conform to be considered acceptable for their intended use.
[[Page 31508]]
``Conformance to specification'' means that the drug substance and
drug product, when tested according to the listed analytical
procedures, will meet the listed acceptance criteria. Specifications
are binding quality standards that are proposed and justified by the
manufacturer, and approved by regulatory authorities.
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, 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.
1.1 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/
biological products to support new marketing applications.
1.2 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/
polypeptides, heparins, vitamins, cell metabolites, DNA products,
allergenic extracts, conventional vaccines, cells, whole blood, and
cellular blood components.
This document does not recommend specific test procedures or
acceptance criteria that should be established for the proposed
value, nor does it apply to the regulation of preclinical and/or
clinical research material.
2.0 General Principles for Consideration in Setting Specifications
2.1 Characterization
Characterization of a biotechnological/biological product (which
includes the determination of physicochemical properties, biological
activity, immunochemical properties, purity, and impurities) 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/clinical studies, data
from lots used for demonstration of manufacturing consistency, and
relevant development data, such as those arising from analytical
procedures and stability studies.
Extensive characterization usually is performed only 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 (primary and working) which will serve for
biological assay and physicochemical testing of production lots.
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 has 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/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
during 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. Such
technologies 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 which describes the
specific ability or capacity of a product to achieve its intended
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/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.
Although mimicking the biological activity in the clinical situation
is not necessary, a correlation between the expected clinical
response and the activity in the biological assay should be
established.
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 correlates 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.
2.1.3 Immunochemical properties
When an antibody is the desired product, its immunological
properties should be fully
[[Page 31509]]
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/drug products, the protein molecule may
need to be examined using immunochemical procedures (e.g., 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/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 have properties comparable to the desired
product, they are considered product-related substances and not
impurities (see 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/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 isolated, the identity of these materials should
be determined as a minimum requirement and, where possible, their
biological activities should be evaluated.
Process-related impurities encompass those that are derived from
the manufacturing process, i.e., derived from the culture (e.g.,
inducers, antibiotics, or media components) or from downstream
processing (see appendix section 6.2.1). Product-related impurities
(e.g., certain degradation products) are molecular variants arising
from processing or during storage, which 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 for 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. Such technologies 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/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 or drug substance/drug product specifications (see
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/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 measurement of biological activity to determine
manufacturing parameters, such as for 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/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/drug product
which 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 on 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 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 points where data serve to confirm consistency of the process
during the production of either the drug substance or the drug
product. The in-process test results may be recorded as action
limits or reported as acceptance criteria. Monitoring for the
presence of mycoplasma and adventitious virus at the end of a cell
culture harvest and/or other stages is an example of testing for
which in-process acceptance criteria should be set. Performing
[[Page 31510]]
such testing may eliminate the need for testing of the drug
substance/drug product (section 2.3.1).
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, should be further refined as
increased 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 acceptable 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/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/
biological products, generally include, but are not limited to,
tests for sterility, endotoxins, bioburden, volume in container,
uniformity of dosage forms, 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/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/validation, 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/clinical studies, lots used for
demonstration of manufacturing consistency, and relevant development
data, such as those arising from analytical procedures and stability
studies.
In some cases, testing at production stages rather than testing
the finished drug substance or drug product 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. 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/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 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) for a drug
substance can be qualitative in nature and, generally, need not be
highly sensitive. 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
Since the absolute purity of biotechnological/biological
products is difficult to determine and the results are method-
dependent (section 2.1.4), the purity of the drug substance is
usually estimated by a combination of methods.
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 culture media, host cell proteins, DNA,
[[Page 31511]]
monoclonal antibodies and chromatographic media used in
purification, solvents/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 resulting from processing or from
storage.
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.
4.1.4 Potency
A relevant, validated potency assay (section 2.1.2) should be
part of the specifications for a biological/biotechnological drug
substance and/or drug product. When an appropriate potency assay is
used for the drug product, an alternative method (physicochemical
and/or biological) may suffice for quantitative assessment at the
drug substance stage (section 4.2.4). 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 reference standard/material
independent. 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 forms, and moisture content for lyophilized
drug products. If appropriate, testing for uniformity of dosage form
may be performed as in-process controls and corresponding acceptance
criteria are set.
4.2.1 Appearance/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 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 and generally need not be highly sensitive. 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 increase in the manufacture 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 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 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 excipients and impurities including degradation
products inherent in the drug product.
4.2.4 Potency
A relevant, validated potency assay (section 2.1.2) should be
part of the specifications for a biological/biotechnological 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 (section 4.1.4).
4.2.5 Quantity
The quantity of the drug substance in the drug product, usually
based on protein content, 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 which the drug substance or drug product or
materials at other stages of their manufacture should meet to
conform with the specification of the results of analytical
procedures.
Action limits: An action limit is an internal (in-house) value
used to assess the consistency of the process at less critical
steps. These limits are the responsibility of the manufacturer.
Biological activity: Biological activity describes the specific
ability or capacity of the product to achieve its intended
biological effect. Potency is the quantitative measure of the
biological activity.
Contaminants: Any adventitiously introduced materials (e.g.,
chemical, biochemical, or microbial species) in the drug substance/
drug product not intended to be part of the manufacturing process.
Degradation products: Degradation products are 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 processing and/or storage (e.g.,
deamidation, oxidation, aggregation, proteolysis). Degradation
products may be either product-related substances or product-related
impurities.
Desired product: The protein that is expected from the DNA
sequence and anticipated post-translational modifications (including
glycoforms) and intended downstream processing necessary 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 drug substance is the
material which 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 and other components,
such as buffers.
Excipient: An ingredient added intentionally to the drug product
or drug substance which should not have pharmacological properties
in the used quantity.
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 added buffer components). It
may be either process- or product-related.
Potency: Potency is 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,
culture (e.g., inducers, antibiotics, or media components), or from
downstream processing (e.g., processing reagents or column
leachables).
Product-related impurities: Product-related impurities are
molecular variants of the desired product arising from processing or
during storage (e.g., certain degradation products) which do not
have properties comparable to those of the desired product with
respect to activity, efficacy, and safety.
[[Page 31512]]
Product-related substances: Product-related substances are
molecular variants of the desired product 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.
Raw material: Raw material is a collective name for substances
or components used in the manufacture of the drug substance or drug
product.
Reference standards/materials: In addition to the existing
international/national standards, it is usually necessary to create
in-house reference materials.
-- In-house primary reference material: A primary reference
material is 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: The in-house working
reference material is a material prepared similarly to the primary
reference material and 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.
Specification: A specification is a list of tests, references to
analytical procedures, and appropriate acceptance criteria with
numerical limits, ranges, or other criteria for the tests described,
which establishes the set of criteria to which a drug substance or
drug product or materials at other stages of their manufacture
should conform to be considered acceptable for its intended use.
6.0 Appendices
6.1 Appendix for Physicochemical Characterization
This appendix provides examples of technical approaches which
might be considered for structural characterization/confirmation and
evaluation of physicochemical properties of the desired 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. Such technologies should be utilized when
appropriate.
6.1.1 Structural characterization/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
protein, or the natural counterpart, if considered necessary, taking
into account the size of the molecule. 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 (N-) and carboxy (C)-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 protein.
(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 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.
Validated peptide mapping is frequently an appropriate method to
confirm desired product structure/identity for lot release purposes.
(e) Sulfhydryl group(s) and disulfide bridges
If, based on the gene sequence for the desired protein, 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 acid) 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/size
Molecular weight (or size) is determined using size exclusion
chromatography, SDS-polyacrylamide gel electrophoresis (under
reducing and/or nonreducing conditions), mass spectrometry, and/or
other appropriate techniques.
(b) Isoform pattern
This is determined by isoelectrical 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 UV/visible wavelength (e.g., 280 nanometers). The
extinction coefficient is determined using UV/visible
spectrophotometry on a solution having a known protein content as
determined by techniques such as amino acids compositional analysis
or nitrogen determination.
(d) Electrophoretic patterns
Electrophoretic patterns and data on identity, homogeneity, and
purity of the desired product/drug substance obtained by
polyacrylamide gel electrophoresis, isoelectric focusing, SDS-
polyacrylamide gel electrophoresis, Western-Blot, capillary
electrophoresis, or other suitable procedures are determined as
appropriate.
(e) Liquid chromatographic patterns
Chromatographic patterns and data on the identity, homogeneity,
and purity of the desired product/drug substance obtained by size
exclusion chromatography, reverse-phase liquid chromatography, ion-
exchange liquid chromatography, affinity chromatography, or other
suitable procedures are determined as appropriate.
(f) Spectroscopic profiles
The ultraviolet 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. Such technologies should be utilized when appropriate.
6.2.1 Process-related impurities
These are derived from the manufacturing process (section 2.1.4)
and are classified into three major categories: Cell substrate-
derived, culture-derived, and downstream-derived.
(a) Cell substrate-derived impurities include proteins/
polypeptides derived from the host organism; nucleic acid (host cell
generic/vector/total DNA); polysaccharides; viruses. For host cell
proteins, a sensitive immunoassay capable of detecting a wide range
of protein impurities is generally utilized. The polyclonal antibody
utilized in the test is generated from a crude preparation of a mock
production organism, i.e., a production cell minus the product-
coding gene. The level of DNA from host cells can be detected by
direct analyses on the product (such as hybridization techniques)
and/or by spiking experiments (laboratory scale) demonstrating the
removal of nucleic acid by the purification process. For
intentionally introduced viruses, the ability of the manufacturing
process to remove/inactivate viruses should be demonstrated as
described in the ICH guidance Q5A ``Viral Safety Evaluation of
Biotechnology Products Derived from Cell Lines of Human or Animal
Origin.''
[[Page 31513]]
(b) Culture-derived impurities include inducers
(polynucleotides, viruses) antibiotics, serum, other media
components.
(c) Downstream-derived impurities include enzymes, chemical/
biochemical processing reagents (e.g., cyanogen bromide, guanidine,
oxidizing and reducing agents), inorganic salts (e.g., heavy metals,
arsenic, non metallic ion), solvents, carrier/ligands (e.g.,
monoclonal antibodies), other leachables.
6.2.2 Product-related impurities
The following represents the most frequently encountered
molecular variants of the desired product and lists relevant
technology for their assessment:
(a) Truncated forms. Cellular peptidases may catalyze the
removal of amino acids or catalyze internal cleavages. This may be
detected by HPLC or SDS-PAGE. Peptide mapping may be useful,
depending on the property of the variant.
(b) Deamidated, isomerized, mismatched S-S linked, oxidized
forms may need considerable effort in isolation and characterization
in order to identify the type of chemical modification(s) and amino
acid residue(s) involved. Chromatographic and/or electrophoretic
methods (e.g., HPLC, capillary electrophoresis, mass spectroscopy,
circular dichroism) may be utilized to isolate and characterize such
variants.
(c) The category of aggregates includes dimers and higher
multiples of the molecular entity. These are generally resolved from
the active moiety and quantitated by size exclusion chromatography
(e.g., SE-HPLC). Degradants identified from stability studies as
being generated in significant amounts should be tested for and
monitored against appropriately established acceptance criteria.
Dated: June 2, 1998.
William K. Hubbard,
Associate Commissioner for Policy Coordination.
[FR Doc. 98-15193 Filed 6-8-98; 8:45 am]
BILLING CODE 4160-01-F
