3. CONTENTS:-
ďWhat is Validation?
ďCycle of analytical methods.
ďTypes of analytical procedures to be validated.
ďConsiderations prior to method validation
ďTypical analytical performance characteristics used in method validation.
ďRevalidation may be necessary in following circumstances.
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4. WHAT IS VALIDATION???
⢠âValidation of an analytical procedure is the process by
which it is established, by laboratory studies, that the
performance characteristics of the procedure meet the
requirements for its intended use.â
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5. CYCLE OF ANALYTICAL METHODS : -
⢠The analytical method validation activity is not a one - time
study. This is illustrated and summarized in the life cycle of an
analytical procedure in Figure 1.
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6. TYPES OF ANALYTICAL PROCEDURES
TO BE VALIDATED.
⢠Identification tests.
⢠Quantitative tests for impurities' content.
⢠Limit tests for the control of impurities.
⢠Quantitative tests of the active moiety in samples of drug.
⢠substance or drug product or other selected component(s) in the
drug product.
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7. CONSIDERATIONS PRIOR TO METHOD
VALIDATION
⢠Suitability of Instrument
â Status of Qualification and Calibration
⢠Suitability of Materials
â Status of Reference Standards, Reagents, etc.
⢠Suitability of Analyst
â Status of Training and Qualification Records
⢠Suitability of Documentation
â Written analytical procedure and proper approved protocol with pre-established acceptance
criteria.
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8. TYPICAL ANALYTICAL PERFORMANCE
CHARACTERISTICS USED IN METHOD
VALIDATION.⢠Specificity (Selectivity)
⢠Linearity
⢠Range
⢠Accuracy
⢠Precision
⢠Detection Limit
⢠Quantitation Limit
⢠Robustness
⢠Ruggedness
⢠System Suitability Testing
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9. -signifies that this characteristic is not normally evaluated.
+ signifies that this characteristic is normally evaluated.
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10. 1. SPECIFICITY (SELECTIVITY)
⢠The ability to detect the analyte of interest in the presence of interfering substances
(typically impurities, degradants, matrix).
A. 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 from
samples containing the analyte, coupled with negative results from samples which do not
contain the analyte.
⢠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.
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11. 2. Assay and impurity test:
a. Impurities are available
ď˘ For the assay , this should involve demonstration of the discrimination of
the analyte in the presence of impurities and/or excipients.
ď˘ This can be done by spiking pure substances with appropriate levels of
impurities and/or excipients and demonstrating that the assay result is
unaffected by the presence of these materials.
ď˘ 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.
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12. b. Impurities are not available
ď˘ 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.
ď˘ As appropriate, this should include samples stored under relevant stress
conditions: light, heat, humidity, acid/base hydrolysis and oxidation.
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13. 2.LINEARITY
ď˘ Ability to obtain test results that are directly (or by a well-defined
mathematical transformation) proportional to the concentration of analyte
in samples within a given range.
ď˘ The range of an analytical procedure is the interval between the upper and
lower levels of analyte (including these levels) that have been
demonstrated to be determined with a suitable level of precision, accuracy,
and linearity
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14. DETERMINATION OF LINEARITY AND RANGE
ď˘ For establishment of linearity, minimum 5 concentrations are recommended.
ď˘ Linearity results should be established by appropriate statistical methods.
y = 0.0868x + 0.019
R² = 0.9988
0
0.2
0.4
0.6
0.8
1
0 2 4 6 8 10 12
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15. ď˘ Transformations are also acceptable and may include log,
square root, or reciprocal (other transformations are
acceptable)
y = 0.3671x - 0.4296
R² = 0.9515
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
0 2 4 6
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16. y = 0.246x + 0.004
R² = 0.9982
0
0.2
0.4
0.6
0.8
1
1.2
1.4
0 2 4 6
If linearity is not attainable, a nonlinear model may be
used. The goal is to have a model (whether linear or
nonlinear) that describes closely the concentration-
response relationship.
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17. 3.RANGE :-
ďDEF: âThe range of an analytical procedure is the interval between the
upper and lower concentration (amounts) of analyte in the sample
(including these concentrations) for which it has been demonstrated
that the analytical procedure has a suitable level of precision, accuracy
and linearity.â
ďThe specified range is normally derived from linearity studies and
depends on the intended application of the procedure.
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18. 4.ACCURACY :-
ďź ACCURACY of an analytical method is the closeness of test results obtained by that
method to the true value.
ďź DETERMINATION-Accuracy should be established across the specified range of the
analytical procedure.
ďź ASSAY
Drug Substance
Drug Product
High Accuracy Less Accuracy
(Less Precision) (High Precision)
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19. 5.PRECISION :-
PRECISION of an analytical method is the degree of agreement among individual test
results when the method is applied repeatedly to multiple samplings of a homogenous
sample.
DETERMINATION- A sufficient number of aliquots of a homogeneous sample are
assayed to be able to calculate statistically valid estimates of standard deviation or relative
standard deviation.
⢠Repeatability
⢠Intermediate precision
⢠Reproducibility
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20. 6. DETECTION LIMIT &
7.QUANTITATION LIMIT:-
DETECTION LIMIT of an individual analytical procedure is the lowest amount of
analyte in a sample which can be detected but not necessarily quantitated, under the stated
experimental conditions.
QUANTITATION LIMIT of an individual analytical
procedure is the lowest amount of analyte in a sample which can be
quantitatively determined with suitable precision and accuracy.
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21. DETERMINATION OF LOD & LOQ
Limit of Detection
ď˘ Method
ďź Based on visual evaluation
ďź Based on standard
deviation of response and
slope
LOD = 3.3 Ď / Slope
ďź Signal to noise ratio 2:1 or
3:1
Limit of Quantitation
ď˘ Method
ďź Based on standard
deviation of response and
slope
ďź Based on visual evaluation
LOD = 10 Ď / Slope
ďź Signal to noise ratio 10:1
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22. 8. ROBUSTNESS :-
ď˘ The robustness of an analytical procedure is a measure of its capacity to remain
unaffected by small, but deliberate variations in method parameters and provides an
indication of its reliability during normal usage.
ď˘ 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, such as:
⢠Use solution within 24 hours
⢠Maintain temperature below 25 degrees
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23. ď˘ In the case of liquid chromatography, examples of typical variations
are:
ďź influence of variations of pH in a mobile phase
ďź influence of variations in mobile phase composition
ďź different columns (different lots and/or suppliers)
ďź temperature
ďź flow rate
ď˘ In the case of gas-chromatography, examples of typical variations are:
ďź different columns (different lots and/or suppliers)
ďź temperature
ďź flow rate
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24. 9.RUGGEDNESS
ď DEF:-âThe ruggedness of an analytical method is the degree of reproducibility of test results
obtained by the analysis of the same samples under a variety of conditions, such as different
laboratories, different analysts, different instruments, different days, etc.
ď Ruggedness is normally expressed as the lack of influence on test results of operational and
environmental variables of the analytical method. Ruggedness is a measure of reproducibility
of test results under the variation in conditions normally expected from laboratory to laboratory
and from analyst to analystâ.
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25. 10.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.
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