[Federal Register Volume 61, Number 46 (Thursday, March 7, 1996)]
[Notices]
[Pages 9316-9319]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-5296]




[[Page 9315]]


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Part VI





Department of Health and Human Services





_______________________________________________________________________



Food and Drug Administration



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

  Federal Register / Vol. 61, No. 46 / Thursday, March 7, 1996 / 
Notices  

[[Page 9316]]



DEPARTMENT OF HEALTH AND HUMAN SERVICES

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


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

AGENCY: Food and Drug Administration, HHS.

ACTION: Notice.

-----------------------------------------------------------------------

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

DATES: Written comments by June 5, 1996.

ADDRESSES: Submit written comments on the draft guideline to the 
Dockets Management Branch (HFA-305), Food and Drug Administration, 
12420 Parklawn Dr., rm. 1-23, Rockville, MD 20857. Copies of the draft 
guideline are available from the Division of Communications Management 
(HFD-210), Center for Drug Evaluation and Research, Food and Drug 
Administration, 7500 Standish Pl., Rockville, MD 20855, 301-594-1012. 
An electronic version of this draft guideline is also available via 
Internet by connecting to the CDER file transfer protocol (FTP) server 
(CDVS2.CDER.FDA.GOV).

FOR FURTHER INFORMATION CONTACT:
    Regarding the guideline: Eric B. Sheinin, Center for Drug 
Evaluation and Research (HFD-830), Food and Drug Administration, 5600 
Fishers Lane, Rockville, MD 20857, 301-827-2001.
    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.
    At a meeting held on November 29, 1995, the ICH Steering Committee 
agreed that a draft guideline entitled ``Validation of Analytical 
Procedures: Methodology'' should be made available for public comment. 
The draft guideline 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. Ultimately, FDA intends to adopt the ICH 
Steering Committee's final guideline.
    In the Federal Register of March 1, 1995 (60 FR 11260), the agency 
published a final 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 draft 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.
    In the past, guidelines have generally been issued under 
Sec. 10.90(b) (21 CFR 10.90(b)), which provides for the use of 
guidelines to state procedures or standards of general applicability 
that are not legal requirements but are acceptable to FDA. The agency 
is now in the process of revising Sec. 10.90(b). Although this draft 
guideline does not create or confer any rights for or on any person and 
does not operate to bind FDA, it does represent the agency's current 
thinking on the validation of analytical procedures.
    Interested persons may, on or before June 5, 1996, submit written 
comments on the draft 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 draft guideline and received comments may be seen in the 
office above between 9 a.m. and 4 p.m., Monday through Friday.
    The text of the draft guideline follows:

Extension of ICH Text on 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.
    All relevant data collected during validation and formulae used 
for calculating

[[Page 9317]]

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 
required 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, 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. Alternatively, for less discriminating procedures, it 
may be acceptable to demonstrate that these impurities can still be 
determined with appropriate accuracy and precision.

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

    Linearity should be established 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 established by visual evaluation 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 5 
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 
product, from 80 to 120 percent of the test concentration;
     For the determination of an impurity, from the 
quantitation limit (QL) or from 50 percent of the specification of 
each impurity, whichever is greater, to 120 percent of the 
specification; and
     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 is used, linearity should cover the 
range from QL or from 50 percent of the specification of each 
impurity, whichever is greater, to 120 percent of the assay 
specification;
     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. For example, if the specifications for a controlled 
released product cover a region from 20 percent, after

[[Page 9318]]

1 hour, up to 90 percent, after 24 hours, the validated range would 
be 0-110 percent of the label claim.

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 concurrently determined when precision, 
linearity, and specificity data are acquired.

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 concurrently determined when precision, 
linearity, and specificity data are acquired.

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 acceptable to compare 
results obtained by an independent procedure (see section 1.2.). The 
response factor of the drug substance can be used.

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).
    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 non-instrumental 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 acceptable.

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

    The detection limit (DL) may be expressed as:

                                                                        
                                                                        
                      3.3                                               
                                                               
       DL=        -----------                                           
                       S                                                
                                                                        

    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.
    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 non-instrumental or 
instrumental. Approaches other than those listed below may be 
acceptable.

7.1. Based on Visual Evaluation

    Visual evaluation may be used for non-instrumental 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.

[[Page 9319]]

7.2. 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 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:

                                                                        
                                                                        
                   10                                                
       QL=        -----------                                           
                       S                                                
                                                                        

    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:

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.
Typical variations are:
     Stability of analytical solutions
     Different equipment
     Different analysts
In the case of liquid chromatography, 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, 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 constitute an 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: February 27, 1996.
William K. Hubbard,
Associate Commissioner for Policy Coordination.
[FR Doc. 96-5296 Filed 3-6-96; 8:45 am]
BILLING CODE 4160-01-F