[Federal Register Volume 62, Number 96 (Monday, May 19, 1997)]
[Notices]
[Pages 27464-27467]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-13063]



[[Page 27463]]

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Part V





Department of Health and Human Services





_______________________________________________________________________



Food and Drug Administration



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International Conference on Harmonisation; Guideline on the Validation 
of Analytical Procedures: Methodology; Availability; Notice

  Federal Register / Vol. 62, No. 96 / Monday, May 19, 1997 / Notices  

[[Page 27464]]


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DEPARTMENT OF HEALTH AND HUMAN SERVICES

Food and Drug Administration
[Docket No. 96D-0030]


International Conference on Harmonisation; Guideline on the 
Validation of Analytical Procedures: Methodology; Availability

AGENCY: Food and Drug Administration, HHS.

ACTION: Notice.

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SUMMARY: The Food and Drug Administration (FDA) is publishing a 
guideline entitled, ``Validation of Analytical Procedures: 
Methodology.'' The guideline was prepared under the auspices of the 
International Conference on Harmonisation of Technical Requirements for 
Registration of Pharmaceuticals for Human Use (ICH). The guideline 
provides recommendations on how to consider various validation 
characteristics for each analytical procedure. The guideline is an 
extension to the ICH guideline entitled, ``Text on Validation of 
Analytical Procedures.''

DATES: Effective May 19, 1997. Submit written comments at any time.

ADDRESSES: Submit written comments on the guideline to the Dockets 
Management Branch (HFA-305), Food and Drug Administration, 12420 
Parklawn Dr., rm. 1-23, Rockville, MD 20857. Copies of the guideline 
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.

FOR FURTHER INFORMATION CONTACT:
    Regarding the guideline: Linda L. Ng, Center for Drug Evaluation 
and Research (HFD-570), Food and Drug Administration, 5600 Fishers 
Lane, Rockville, MD 20857, 301-827-1050.
    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 March 7, 1996 (61 FR 9316), FDA 
published a draft tripartite guideline entitled, ``Validation of 
Analytical Procedures: Methodology.'' The notice gave interested 
persons an opportunity to submit comments by June 5, 1996.
    After consideration of the comments received and revisions to the 
guideline, a final draft of the guideline was submitted to the ICH 
Steering Committee and endorsed by the three participating regulatory 
agencies at the ICH meeting held on November 6, 1996.
    In the Federal Register of March 1, 1995 (60 FR 11260), the agency 
published a guideline entitled, ``Text on Validation of Analytical 
Procedures.'' The guideline presents a discussion of the 
characteristics that should be considered during the validation of the 
analytical procedures included as part of registration applications 
submitted in Europe, Japan, and the United States. The guideline 
discusses common types of analytical procedures and defines basic 
terms, such as ``analytical procedure,'' ``specificity,'' and 
``precision.'' These terms and definitions are meant to bridge the 
differences that often exist between various compendia and regulators 
of the European Union, Japan, and the United States.
    This guideline provides guidance and recommendations on how to 
consider the various validation characteristics for each analytical 
procedure. In some cases, (for example, the demonstration of 
specificity) the overall capabilities of a number of analytical 
procedures in combination may be investigated to ensure the quality of 
the drug substance or drug product.
    This guideline represents the agency's current thinking on the 
validation of analytical procedures. 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 guidelines, the public is encouraged to submit 
written comments with new data or other new information pertinent to 
this guideline. The comments in the docket will be periodically 
reviewed, and, where appropriate, the guideline 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 
final guideline 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 guideline 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 guideline is 
available via Internet using the World Wide Web (WWW) (http://
www.fda.gov/cder/guidance.htm).
    The text of the guideline follows:

Validation of Analytical Procedures: Methodology

Introduction

    This document is complementary to the ICH guideline entitled 
``Text on Validation of Analytical Procedures,'' which presents a 
discussion of the characteristics that should be considered during 
the validation of analytical procedures. Its purpose is to provide 
some guidance and recommendations on how to consider the various 
validation characteristics for each analytical procedure. In some 
cases (for example, demonstration of specificity), the overall 
capabilities of a number of analytical procedures in combination may 
be investigated in order to ensure the quality of the drug substance 
or drug product. In addition, the document provides an indication of 
the data that should be presented in a new drug application.

[[Page 27465]]

    All relevant data collected during validation and formulae used 
for calculating validation characteristics should be submitted and 
discussed as appropriate.
    Approaches other than those set forth in this guideline may be 
applicable and acceptable. It is the responsibility of the applicant 
to choose the validation procedure and protocol most suitable for 
their product. However, it is important to remember that the main 
objective of validation of an analytical procedure is to demonstrate 
that the procedure is suitable for its intended purpose. Due to 
their complex nature, analytical procedures for biological and 
biotechnological products in some cases may be approached 
differently than in this document.
    Well-characterized reference materials, with documented purity, 
should be used throughout the validation study. The degree of purity 
necessary depends on the intended use.
    In accordance with the parent document, and for the sake of 
clarity, this document considers the various validation 
characteristics in distinct sections. The arrangement of these 
sections reflects the process by which an analytical procedure may 
be developed and evaluated.
    In practice, it is usually possible to design the experimental 
work such that the appropriate validation characteristics can be 
considered simultaneously to provide a sound, overall knowledge of 
the capabilities of the analytical procedure, for instance: 
Specificity, linearity, range, accuracy, and precision.

1. Specificity

    An investigation of specificity should be conducted during the 
validation of identification tests, the determination of impurities, 
and the assay. The procedures used to demonstrate specificity will 
depend on the intended objective of the analytical procedure.
    It is not always possible to demonstrate that an analytical 
procedure is specific for a particular analyte (complete 
discrimination). In this case, a combination of two or more 
analytical procedures is recommended to achieve the necessary level 
of discrimination.

1.1. Identification

    Suitable identification tests should be able to discriminate 
between compounds of closely related structures which are likely to 
be present. The discrimination of a procedure may be confirmed by 
obtaining positive results (perhaps by comparison with a known 
reference material) from samples containing the analyte, coupled 
with negative results from samples which do not contain the analyte. 
In addition, the identification test may be applied to materials 
structurally similar to or closely related to the analyte to confirm 
that a positive response is not obtained. The choice of such 
potentially interfering materials should be based on sensible 
scientific judgment with a consideration of the interferences that 
could occur.

1.2. Assay and Impurity Test(s)

    For chromatographic procedures, representative chromatograms 
should be used to demonstrate specificity, and individual components 
should be appropriately labeled. Similar considerations should be 
given to other separation techniques.
    Critical separations in chromatography should be investigated at 
an appropriate level. For critical separations, specificity can be 
demonstrated by the resolution of the two components which elute 
closest to each other.
    In cases where a nonspecific assay is used, other supporting 
analytical procedures should be used to demonstrate overall 
specificity. For example, where a titration is adopted to assay the 
drug substance for release, the combination of the assay and a 
suitable test for impurities can be used.
    The approach is similar for both assay and impurity tests:

1.2.1. Impurities Are Available

    For the assay, this should involve demonstration of the 
discrimination of the analyte in the presence of impurities and/or 
excipients; practically, this can be done by spiking pure substances 
(drug substance or drug product) with appropriate levels of 
impurities and/or excipients and demonstrating that the assay result 
is unaffected by the presence of these materials (by comparison with 
the assay result obtained on unspiked samples). For the impurity 
test, the discrimination may be established by spiking drug 
substance or drug product with appropriate levels of impurities and 
demonstrating the separation of these impurities individually and/or 
from other components in the sample matrix.

1.2.2. Impurities Are Not Available

    If impurity or degradation product standards are unavailable, 
specificity may be demonstrated by comparing the test results of 
samples containing impurities or degradation products to a second 
well-characterized procedure, e.g., pharmacopoeial method or other 
validated analytical procedure (independent procedure). As 
appropriate, this should include samples stored under relevant 
stress conditions: Light, heat, humidity, acid/base hydrolysis, and 
oxidation.
     For the assay, the two results should be compared.
     For the impurity tests, the impurity profiles should be 
compared.
    Peak purity tests may be useful to show that the analyte 
chromatographic peak is not attributable to more than one component 
(e.g., diode array, mass spectrometry).

2. Linearity

    A linear relationship should be evaluated across the range (see 
section 3) of the analytical procedure. It may be demonstrated 
directly on the drug substance (by dilution of a standard stock 
solution) and/or separate weighings of synthetic mixtures of the 
drug product components, using the proposed procedure. The latter 
aspect can be studied during investigation of the range.
    Linearity should be evaluated by visual inspection of a plot of 
signals as a function of analyte concentration or content. If there 
is a linear relationship, test results should be evaluated by 
appropriate statistical methods, for example, by calculation of a 
regression line by the method of least squares. In some cases, to 
obtain linearity between assays and sample concentrations, the test 
data may have to be subjected to a mathematical transformation prior 
to the regression analysis. Data from the regression line itself may 
be helpful to provide mathematical estimates of the degree of 
linearity.
    The correlation coefficient, y-intercept, slope of the 
regression line, and residual sum of squares should be submitted. A 
plot of the data should be included. In addition, an analysis of the 
deviation of the actual data points from the regression line may 
also be helpful for evaluating linearity.
    Some analytical procedures, such as immunoassays, do not 
demonstrate linearity after any transformation. In this case, the 
analytical response should be described by an appropriate function 
of the concentration (amount) of an analyte in a sample.
    For the establishment of linearity, a minimum of five 
concentrations is recommended. Other approaches should be justified.

3. Range

    The specified range is normally derived from linearity studies 
and depends on the intended application of the procedure. It is 
established by confirming that the analytical procedure provides an 
acceptable degree of linearity, accuracy, and precision when applied 
to samples containing amounts of analyte within or at the extremes 
of the specified range of the analytical procedure.
    The following minimum specified ranges should be considered:
     For the assay of a drug substance or a finished (drug) 
product: Normally from 80 to 120 percent of the test concentration;
     For content uniformity: Covering a minimum of 70 to 130 
percent of the test concentration, unless a wider, more appropriate 
range, based on the nature of the dosage form (e.g., metered dose 
inhalers), is justified;
     For dissolution testing: +/-20 percent over the 
specified range; e.g., if the specifications for a controlled 
released product cover a region from 20 percent, after 1 hour, up to 
90 percent, after 24 hours, the validated range would be 0-110 
percent of the label claim;
     For the determination of an impurity: From the 
reporting level of an impurity\1\ to 120 percent of the 
specification;
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    \1\See sections on ``Reporting Impurity Content of Batches'' of 
the corresponding ICH guideline entitled ``Impurities in New Drug 
Substances'' (61 FR 372, January 4, 1996) and draft guideline 
``Impurities in New Drug Products'' (61 FR 11268, March 19, 1996).
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     For impurities known to be unusually potent or to 
produce toxic or unexpected pharmacological effects, the detection/
quantitation limit should be commensurate with the level at which 
the impurities must be controlled.
    Note: For validation of impurity test procedures carried out 
during development, it may be necessary to consider the range around 
a suggested (probable) limit;
     If assay and purity are performed together as one test 
and only a 100 percent standard

[[Page 27466]]

is used, linearity should cover the range from the reporting level 
of the impurities\2\ to 120 percent of the assay specification.
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    \2\ Ibid.
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4. Accuracy

    Accuracy should be established across the specified range of the 
analytical procedure.

4.1. Assay

4.1.1. Drug substance:

    Several methods of determining accuracy are available:
    (a) Application of an analytical procedure to an analyte of 
known purity (e.g., reference material);
    (b) Comparison of the results of the proposed analytical 
procedure with those of a second well-characterized procedure, the 
accuracy of which is stated and/or defined (independent procedure, 
see section 1.2.);
    (c) Accuracy may be inferred once precision, linearity, and 
specificity have been established.

4.1.2. Drug product:

    Several methods for determining accuracy are available:
    (a) Application of the analytical procedure to synthetic 
mixtures of the drug product components to which known quantities of 
the drug substance to be analyzed have been added;
    (b) In cases where it is impossible to obtain samples of all 
drug product components, it may be acceptable either to add known 
quantities of the analyte to the drug product or to compare the 
results obtained from a second, well-characterized procedure, the 
accuracy of which is stated and/or defined (independent procedure, 
see section 1.2);
    c) Accuracy may be inferred once precision, linearity, and 
specificity have been established.

4.2. Impurities (Quantitation)

    Accuracy should be assessed on samples (drug substance/drug 
product) spiked with known amounts of impurities.
    In cases where it is impossible to obtain samples of certain 
impurities and/or degradation products, it is considered acceptable 
to compare results obtained by an independent procedure (see section 
1.2.). The response factor of the drug substance can be used.
    It should be clear how the individual or total impurities are to 
be determined, e.g., weight/weight or area percent, in all cases 
with respect to the major analyte.

4.3. Recommended Data:

    Accuracy should be assessed using a minimum of 9 determinations 
over a minimum of 3 concentration levels covering the specified 
range (e.g., 3 concentrations/3 replicates each of the total 
analytical procedure).
    Accuracy should be reported as percent recovery by the assay of 
known added amount of analyte in the sample or as the difference 
between the mean and the accepted true value together with the 
confidence intervals.

5. Precision

    Validation of tests for assay and for quantitative determination 
of impurities includes an investigation of precision.

5.1. Repeatability

    Repeatability should be assessed using:
    (a) A minimum of 9 determinations covering the specified range 
for the procedure (e.g., 3 concentrations/3 replicates each); or
    (b) A minimum of 6 determinations at 100 percent of the test 
concentration.

5.2. Intermediate Precision

    The extent to which intermediate precision should be established 
depends on the circumstances under which the procedure is intended 
to be used. The applicant should establish the effects of random 
events on the precision of the analytical procedure. Typical 
variations to be studied include days, analysts, equipment, etc. It 
is not necessary to study these effects individually. The use of an 
experimental design (matrix) is encouraged.

5.3. Reproducibility

    Reproducibility is assessed by means of an interlaboratory 
trial. Reproducibility should be considered in case of the 
standardization of an analytical procedure, for instance, for 
inclusion of procedures in pharmacopoeias. These data are not part 
of the marketing authorization dossier.

5.4. Recommended Data

    The standard deviation, relative standard deviation (coefficient 
of variation), and confidence interval should be reported for each 
type of precision investigated.

6. Detection Limit

    Several approaches for determining the detection limit are 
possible, depending on whether the procedure is noninstrumental or 
instrumental. Approaches other than those listed below may be 
acceptable.

6.1. Based on Visual Evaluation

    Visual evaluation may be used for noninstrumental methods but 
may also be used with instrumental methods.
    The detection limit is determined by the analysis of samples 
with known concentrations of analyte and by establishing the minimum 
level at which the analyte can be reliably detected.

6.2. Based on Signal-to-Noise

    This approach can only be applied to analytical procedures which 
exhibit baseline noise. Determination of the signal-to-noise ratio 
is performed by comparing measured signals from samples with known 
low concentrations of analyte with those of blank samples and 
establishing the minimum concentration at which the analyte can be 
reliably detected. A signal-to-noise ratio between 3 or 2:1 is 
generally considered acceptable for estimating the detection limit.

6.3 Based on the Standard Deviation of the Response and the Slope

    The detection limit (DL) may be expressed as:
    [GRAPHIC] [TIFF OMITTED] TN19MY97.007
    
where  = the standard deviation of the response
     S = the slope of the calibration curve
The slope S may be estimated from the calibration curve of the 
analyte. The estimate of  may be carried out in a variety 
of ways, for example:

6.3.1. Based on the standard deviation of the blank

    Measurement of the magnitude of analytical background response 
is performed by analyzing an appropriate number of blank samples and 
calculating the standard deviation of these responses.

6.3.2. Based on the calibration curve

    A specific calibration curve should be studied using samples 
containing an analyte in the range of DL. The residual standard 
deviation of a regression line or the standard deviation of y-
intercepts of regression lines may be used as the standard 
deviation.

6.4. Recommended Data

    The detection limit and the method used for determining the 
detection limit should be presented. If DL is determined based on 
visual evaluation or based on signal-to-noise ratio, the 
presentation of the relevant chromatograms is considered acceptable 
for justification.
    In cases where an estimated value for the detection limit is 
obtained by calculation or extrapolation, this estimate may 
subsequently be validated by the independent analysis of a suitable 
number of samples known to be near or prepared at the detection 
limit.

7. Quantitation Limit

    Several approaches for determining the quantitation limit are 
possible, depending on whether the procedure is noninstrumental or 
instrumental. Approaches other than those listed below may be 
acceptable.

7.1. Based on Visual Evaluation

    Visual evaluation may be used for noninstrumental methods, but 
may also be used with instrumental methods.
    The quantitation limit is generally determined by the analysis 
of samples with known concentrations of analyte and by establishing 
the minimum level at which the analyte can be quantified with 
acceptable accuracy and precision.

7.2. Based on Signal-to-Noise

    This approach can only be applied to analytical procedures that 
exhibit baseline noise. Determination of the signal-to-noise ratio 
is performed by comparing measured signals from samples with known 
low concentrations of analyte with those of blank samples and by 
establishing the minimum concentration at which the analyte can be 
reliably quantified. A typical signal-to-noise ratio is 10:1.

7.3. Based on the Standard Deviation of the Response and the Slope

    The quantitation limit (QL) may be expressed as:

[[Page 27467]]

[GRAPHIC] [TIFF OMITTED] TN19MY97.008


where  = the standard deviation of responses
     S = the slope of the calibration curve
The slope S may be estimated from the calibration curve of the 
analyte. The estimate of  may be carried out in a variety 
of ways, for example:

7.3.1. Based on standard deviation of the blank

    Measurement of the magnitude of analytical background response 
is performed by analyzing an appropriate number of blank samples and 
calculating the standard deviation of these responses.

7.3.2. Based on the calibration curve

    A specific calibration curve should be studied using samples 
containing an analyte in the range of QL. The residual standard 
deviation of a regression line or the standard deviation of y-
intercepts of regression lines may be used as the standard 
deviation.

7.4 Recommended Data

    The quantitation limit and the method used for determining the 
quantitation limit should be presented.
    The limit should be subsequently validated by the analysis of a 
suitable number of samples known to be near or prepared at the 
quantitation limit.

8. Robustness

    The evaluation of robustness should be considered during the 
development phase and depends on the type of procedure under study. 
It should show the reliability of an analysis with respect to 
deliberate variations in method parameters.
    If measurements are susceptible to variations in analytical 
conditions, the analytical conditions should be suitably controlled 
or a precautionary statement should be included in the procedure. 
One consequence of the evaluation of robustness should be that a 
series of system suitability parameters (e.g., resolution test) is 
established to ensure that the validity of the analytical procedure 
is maintained whenever used.
    Examples of typical variations are:
     Stability of analytical solutions
     Extraction time
    In the case of liquid chromatography, examples of typical 
variations are:
     Influence of variations of pH in a mobile phase
     Influence of variations in mobile phase composition
     Different columns (different lots and/or suppliers)
     Temperature
     Flow rate
    In the case of gas-chromatography, examples of typical 
variations are:
     Different columns (different lots and/or suppliers)
     Temperature
     Flow rate

9. System Suitability Testing

    System suitability testing is an integral part of many 
analytical procedures. The tests are based on the concept that the 
equipment, electronics, analytical operations, and samples to be 
analyzed constitutean integral system that can be evaluated as such. 
System suitability test parameters to be established for a 
particular procedure depend on the type of procedure being 
validated. See pharmacopoeias for additional information.

    Dated: May 13, 1997.
William K. Hubbard,
Associate Commissioner for Policy Coordination.
[FR Doc. 97-13063 Filed 5-16-97; 8:45 am]
BILLING CODE 4160-01-F