Analytical method validation
approaches
from Development to Launch
Analytical Method Validation (What, Why, When and How much)
Drug Development Phases
Validation Requirement (Innovator Vs Generics & regulatory Perspective)
Validation Prerequisites
Validation Activity Flow
Validation Parameters
System Suitability
Out of Acceptance – case studies
Recent FDA 483’s & Warning Letters
References
Summary recommendations & Conclusions
Q & A session
Topics
RT : Reporting Threshold
DL : Detection Limit
QL : Quantitation Limit
SL : Specification Limit
API : Active Pharmaceutical Ingredient
DS : Drug Substance
DP : Drug Product
IND : Investigational New Drug
CTA : Clinical Trial Application
NDA : New Drug Application
MAA : Marketing Authorization Application
Sample Matrix: Other possible ingredient of drug product except the API
What is Method Validation
The FDA defines the term as :
“Established documented evidence which provides a high degree of assurance that a
specific process will consistently produce a product meeting its pre-determined specifications and quality attributes.” - General Principles of Validation (1987)
ICH guideline :
“A documented program that provides a high degree of assurance that a specific process, method, or system will consistently produce a result meeting pre-determined acceptance criteria.” - Q7A-GMP for active pharmaceutical ingredients (2000)
EU-guideline :
Action of proving, in accordance with GMP-principles that any procedure, process, equipment,
material, activity or system actuallyleads to the expected results.
Method validation is the “process used to confirm that the analytical
procedure employed for a specific test is suitable for its intended use”
Why Method Validation
∗
To obtain reliable analytical results & comply with international regulations
∗
Essential component of the measure that laboratories should employ to ensure
that they produce accurate and reliable results
∗
Universally recognized comprehensive system of quality assurance
∗
Identification of sources and quantitation of potential errors
∗
Determination if method is acceptable for Intended Use
∗
Establish proof that a method can be used for decision making
∗
Satisfy FDA requirements
∗
To meet accreditation requirement
∗
Ensure that the test method give “correct” results
When Method Validation
Method validations are required when
∗
New method is developed
∗
Existing method is significantly modified (optimized)
∗
Existing validated method is applied to a different sample matrix
Method Validation – how much is
adequate
Depends on
•
Phase of drug for which method is to be used
•
The critically of the measurement
•
The scope of the method
Method Validation – how much
contd..
Test method description Validation or Verification requirements
Standard methods with performance data(e.g. compendia method USP/EP etc.)
Verification of performance, but validation may be required if any changes made
in-house developed methods Full validation
Published in the literature without any performance data Full validation
Published in the literature with performance data Verification of performance but more likely full validation required
Changes in implementation of previously validated method -i.e. changes to equipment, reagents, lab environment or staff.
Verification
Existing validated method applied to different matrices, different concentration ranges
Validation - extent will vary - e.g. having similar properties to those of representative matrices
Existing validated method applied to additional analytes Full Validation
Commercial Test Kits - collaboratively tested, third party
evaluation (e.g. AOAC) Verification
Commercial Test Kits - no performance data available,
Different Phases During New Drug Development
Pre-phase-I Phase-I
Phase-III
Filing / Approvals
NDA Phase-II
Phase-II A Phase-II B
Early
phase
Late
phase
Pre-phase-I
:
Pharmacology and toxicology studiesPhase-I
:
Testing the simplest formulation of drug in healthy volunteersPhase-IIA
:
Evaluation of drug for the clinical effectiveness in the target patient population (for fixing the proper and safe dosage range)Phase-II B and Phase-III :
Testing in thousands of patients with proposed marketed formulation after the establishment of safe and clinical effectiveness (Late Phase Development)Drug Product Development and GMP
Full characterization
Full GMP
21 CFR 210, 211
Phase III
Phase I
Phase
II A
Pre-clinical
Validated Method
Standard
screening methods
Phase
II B
Clinical Monitoring Program
Early Phase
Late Phase
•
Pre- Phase1 to Phase I
– Limited validation, focussing on
key method attributes eg. specificity, limits of quantitation
and linearity
•
Up to Phase IIA
– Starting to include accuracy and
precision data to support specifications
•
From Phase IIB to Phase III
– Full validation according to
ICH guidelines will be completed for all analytical methods
prior to submission of marketing applications
Innovator Vs Generics
Generics
Innovator
R & D on API
Preclinical trials
-Method validation
summary
Clinical trials pre -phase I to IIa
(Early Development)
-Full Method
validation
Clinical trials phase IIb to III
(Late Development)
-Validated methods
Post marketing phase IV
Validated
methods: GMP
and GLP
Validated methods
Entering of Generics;
Pharmaceutical
development, Comparability
with Innovator
Validation Parameters defined in ICH & USP
USP ( USP 33, NF 28)
ICH (Q2 (R1))
Specificity Specificity
Linearity & Range Linearity
Accuracy Range
Precision Accuracy
Limit of Detection
Precision
(Repeatability, Intermediate Precision, Reproducibility)
Limit of Quantitation Detection Limit
Ruggedness Quantitation Limit
Assessment of method validation requirements
•What analytes should be detected?
• What are the expected concentration levels?
• What are the sample matrices?
• Are there interfering substances expected, and, if so, should they be detected and quantified?
• Are there any specific legislative or regulatory requirements?
• Should information be qualitative or quantitative?
• What are the required detection and quantitation limits?
• What is the expected concentration range?
•What precision and accuracy is expected?
•How robust should the method be?
•Which type of equipment should be used? Is the method for one specific instrument, or should it be
used by all instruments of the same type?
•Will the method be used in one specific laboratory or should it be applicable in all laboratories at
one side or around the globe?
Prerequisites for analytical method validation
–
Six “M”s
Quality of the
analytical method
M
an
M
achine
qualified calibrated robust qualified
M
ethods
suitable characterised documentedM
ilieu
M
aterial
M
anagement
Validation Activity Flow
Approved SOP for method
validation
Validation Protocol Validation Specifications
Execution of analytical
activity
Meeting the acceptance criteria
Validation Report
Summary of the observed events
Not meeting Acceptance Criteria Initiate the event to
Identify the root cause
Define Corrective action
Required Validation Parameters
Assay Impurities Identification limit quantitative + -+ -Accuracy + -+ -Precision• Repeatability (System Repeatability & Analysis Repeatability)
• Intermediate precision
SPECIFICITY
∗ Specificity is the ability to assess unequivocally the analyte in the presence of
components which may be expected to be present. Typically these might include impurities, degradants, matrix, etc.
∗ Specificity is demonstrated by representative chromatograms of appropriate solutions
which may include but not limited to , reference, selectivity batch, stressed sample, placebo and stressed placebo solutions that contains all compounds for which specificity has to be proven.
Most common techniques are used to determine specificity:
∗ Photo-diode array detector ∗ LC-MS
The chromatographic signal does not
indicate any impurity in either peak.
Spectral evaluation, however, identifies
the peak on the left as impure.
ACCURACY & PRECISION
Accuracy
The closeness of agreement between the value which is accepted either as a conventional true value or an accepted reference value and the value found.
Precision
ACCURACY
∗ Should be established across specified range of analytical procedure.
∗ Should be assessed using a minimum of 3 concentration levels covering the specified
range in presence of sample matrix, each in triplicate (total of 9 determinations).
∗ Should be evaluated as Percent recovery of known amount added.
Test Type Concentration in % w.r.t.
nominal sample concentration
Assay 70-80-100-120-130
Related
Substances a
QL-SL- atleast 1.2 times SL
Content Uniformity 70-100-130
Dissolution 20b-100-120
Residual Solvent QL-SL- atleast 1.2 times SL
Concentration 70% 100% 120%
% Recovery 1 100.6 99.7 99.7
% Recovery 2 100.2 99.9 99.4
% Recovery 3 99.0 100.2 99.2
Mean Recovery 99.9 99.9 99.4
a: using impurity for specified impurity and using active for unspecified degradants
b: it should be below the value at 1st timepoint of profile. Ex. extended release it
may be below 20%.
Concentration 70% 100% 120%
% Recovery 1 100.6 99.7 99.7
% Recovery 2 100.2 99.9 99.4
% Recovery 3 99.0 100.2 99.2
Mean Recovery 99.9 99.9 99.4
PRECISION
∗ The precision of an analytical procedure expresses the closeness of agreement
(degree of scatter) between a series of measurements obtained from multiple sampling of the same homogeneous sample under the prescribed conditions.
Precision may be considered at three levels: repeatability, intermediate precision and reproducibility.
∗ Precision should be investigated using homogeneous, authentic samples. However, if
it is not possible to obtain a homogeneous sample it may be investigated using artificially prepared samples or a sample solution.
∗ Repeatability (System Repeatability & Analysis Repeatability)
Repeatability expresses the precision under the same operating conditions over a short interval of time. Repeatability is also termed intra-assay precision .
∗ Intermediate precision
Intermediate precision expresses within-laboratories variations: different days, different analysts, different equipment, etc.
∗ Reproducibility
Variations affecting method
reproducibility
Precision Intermediate
Precision Reproducibility
Instrument same different different
Batches of accessories e.g.
chrom. columns same different different
Operators same different different
Sample matrices different different different
Concentration different different different
Batches of material, e.g., reagents same different different
Environmental conditions, e.g.,
temperature same different different
Laboratory same same different
PRECISION - System Repeatability
∗ It will be determined by injecting at least 5 consecutive injections of the same solution
. RSD of the response will be evaluated.
Test Type Concentration in % w.r.t. nominal sample concentration
Assay 100
Related Substances SL - individual Impurity & API (for unknown)
Content Uniformity 100
Dissolution 100
Residual Solvent SL
Determination 100% API SL (0.5%) of API
1 19770367 99353
2 19748915 99342
3 19726133 99749
4 19776942 99407
5 19847909 99584
PRECISION - Analysis Repeatability
∗ Should be assessed using a minimum of 3 concentration levels covering the specified
range in presence of sample matrix, each in triplicate (total of 9 determinations). or
∗ It will be determined by analyzing at least 6 sample preparations by one person on
one instrument in same sample set .
∗ Sample should contain all impurities of interest. If single sample does not contain all,
multiple samples can be used or spiking can be preferred.
∗ RSD of the assay will be evaluated (for active as well as impurities).
Determination % API % Imp - A % Imp - B
1 98.9 0.08 0.25
2 99.4 0.09 0.28
3 100.2 0.10 0.26
4 101.1 0.10 0.29
5 99.2 0.11 0.25
6 98.7 0.10 0.25
% RSD 0.9 10.7 6.7
PRECISION - Intermediate Precision
∗ It will be determined by analyzing at least 6 sample preparations each by two different
person, instrument on different day.
∗ Sample should contain all impurities of interest. If single sample does not contain all,
multiple samples can be used or spiking can be preferred.
∗ RSD/Pooled RSD of the assay for all samples will be evaluated (for active as well as
impurities) or Absolute/% relative difference between two analyst can be evaluated.
∗ Intermediate precision may not be needed if reproducibility is performed.
Active Impurity
Determination Analyst 1 Analyst 2 Analyst 1 Analyst 2
1 98.9 100.8 0.25 0.23
2 99.4 100.3 0.28 0.26
3 100.2 101.1 0.26 0.25
4 101.1 99.8 0.29 0.24
5 99.2 100.5 0.25 0.22
PRECISION - Reproducibility
∗ It will be determined by analyzing at least 6 sample preparations each by two different
laboratories.
∗ Sample should contain all impurities of interest. If single sample does not contain all,
multiple samples can be used or spiking can be preferred.
∗ RSD/Pooled RSD of the assay for all samples will be evaluated (for active as well as
impurities) or Absolute/% relative difference between two laboratories can be evaluated.
Active Impurity
Determination laboratory 1 laboratory 2 laboratory 1 laboratory 2
1 98.9 100.8 0.25 0.23
2 99.4 100.3 0.28 0.26
3 100.2 101.1 0.26 0.25
4 101.1 99.8 0.29 0.24
5 99.2 100.5 0.25 0.22
6 98.7 100.1 0.25 0.24
% RSD 0.8 7.7
DETECTION LIMIT & QUANTITATION LIMIT
DETECTION LIMIT : The detection limit of an individual analytical procedure is the lowest amount of analyte in a sample which can be detected but not necessarily quantitated as an exact value.
QUANTITATION LIMIT : The 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.
Based on Visual Evaluation
Based on Signal-to-Noise
Based on the Standard Deviation of the Response and the Slope
Quantitation Limit
When impurity is not available When impurity is available
3 separate solutions are prepared containing the API at a reporting threshold concentration. These three solutions can be prepared with 100% placebo.
3 separate solutions are prepared containing the Impurity at a reporting threshold concentration with 100% API and 100% placebo.
Note:
•Three RT solutions must be prepared from three different stock solutions. •These solutions are analysed and the recovery & repeatability is evaluated. •First Blank injection is considered for S/N ratio calculation.
Quantitation limit: Acceptance Criteria
Method type Concentration Range ≤ Mean % recovery ≤ % RSD ≤ (n=3) Early Phase (IND/CTA) Target QL ≤ RT 50.0 - 150.0 ≤25.0
Late Phase (NDA/MAA) Target QL ≤ RT 70.0 - 130.0 ≤15.0
LINEARITY
The linearity of an analytical procedure is its ability (within a given range) to
obtain test results which are directly proportional to the concentration
(amount) of analyte in the sample.
A linear relationship should be evaluated across the range of the analytical
procedure
at minimum 5 levels
.
Linearity should be evaluated by visual inspection of a plot of signals as a
function of analyte concentration or content.
Test results should be evaluated by appropriate statistical methods, for
example, by calculation of a regression line by the method of least squares.
Correlation coefficient, % RSD of the response factor
can be evaluated.
LINEARITY
Signal height or peak area as a function of analyte concentration
Divide signal data by their respective concentrations, yielding the relative responses.
A graph is plotted with the relative responses on the y-axis and the corresponding concentrations on the x-axis, on a log scale
RANGE
The 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.
ROBUSTNESS
∗
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.
∗
The evaluation of robustness should be considered during the development
phase and depends on the type of procedure under study.
∗
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 method.
∗
Examples of typical variations
∗
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
OTHER ADDITIONAL PARAMATERS
∗ Stability of the Solutions
∗ Filtration Study
∗ Relative Response factor
∗ Automation
∗ Method Equivalency
SYSTEM SUITABILITY
∗
System suitability tests are an integral part of gas and liquid chromatographic
methods. They are used to verify that the resolution and reproducibility of the
chromatographic system are adequate for the analysis to be done. The tests are
based upon the concept that the equipment, electronics, analytical operations,
and samples to be analyze d constitute an integral system that can be evaluated
as such.
∗
System Suitability Test characteristics and limits are recommended as a
component of any analytical method and are established to ensure the validity of
the analytical method whenever used.
Parameters Recommendations
K’ In general k’ ≥ 2.0
R R > 2, between the peak of interest and the closest potential interferent (degradant, internal STD, impurity, excipients, etc…..)
T T ≤ 2
N In general N > 2000
Repeatability RSD ≤ 2.0% (n ≥ 5)
Revalidation & Bracketing Validation
Revalidation is performed under following situations∗ Change in the synthetic route
∗ Changes in sample preparation procedure where recovery or sample matrix effect may
change
∗ Changes in Analyte detection method e.g. Change in UV wavelength, UV to
Fluorescence detector etc.
∗ Changes in Chromatographic Operational parameters ( Column packing, Separation
technique, sample load, etc.)
∗ Elucidation of new Impurities or Degradation products.
Only above conditions are not limited. Case to case evaluation is needed !!
Bracketing approach for validation
∗ Dose Proportional Formulations : Validation can be shown for Lowest strength &
additionally intermediate precision or reproducibility shall be done for Highest strength.
Out of Acceptance case studies
Observation Root cause Corrective action
Accuracy passing at 70 & 100% but failing at 130%.
The peak height of sample and standard solution is higher than max linearity range of UV detector.
Revise the test method to reduce the concentration.
Accuracy is not meeting the acceptance criteria for specified impurity
Impurity was not completely soluble in dilution solvent of the method.
Identify the correct dilution solvent in which impurity is soluble.
Accuracy is failing for impurity at quantitation level (0.05%)
One of the excipient is trapping the API. Acidic sample diluent improved the recovery
Issue with original diluent. Modified the method prior to revalidation
Accuracy is not passing for drug Substances at 130%.
Solubility issue at higher concentration
Method validated in 80-120%.
Linearity test is failing for RSD of Response factor but
correlation coefficient is passing.
Lower concentration solutions (0.05%) injected after 100% level.
Blank injection before lower concentration solution.
% Dissolution is variable during reproducibility test.
Improper homogenization of dissolution media.
FDA- Form 483
∗ There was inadequate method validation specificity data to demonstrate that each
method was capable of distinguishing the active ingredient from its impurities and degradation products.
∗ Specificity studies did not include the minimum stress conditions of acid and base
hydrolysis, oxidation, thermal degradation and photolysis, degradation schematic for the active ingredient that identifies the major degradation products was not included for each product.
∗ Stress studies conducted as part of method validation do not target a minimum
amount of degradation. … a standard period of two hours as commonly used for stress studies with no justification…
∗ Spreadsheets used to calculate linearity, percent recovery, and final assay results for
FDA- Warning Letters
∗ On addition to the example of modifying both compendia methods and customer supplied
methods, we also observed the use of un-validated in-house methods as well as invalidated modifications to in-house methods.
∗ Change control procedures in the laboratory failed to document test method changes to
assure accurate, reliable, and reproducible results. The test method did not state whether a helix was to be used during dissolution testing. A … was reportedly used during method development, validation and daily method runs, but there is no documentation of a … being used in any of the documents.
∗ There is no assurance that qualification or maintenance of the laboratory equipment can
consistently produce valid and accurate analytical results in that numerous examples of test data were invalidated due to instrument malfunction.
∗ Attempts to corroborate data in the validation report with supporting raw data in the
laboratory were difficult and frustrating for the FDA personnel conducting the inspection.
FDA- Warning Letters
∗ OOS accuracy results reported by analyst 3 were never submitted in the final report.
Repeat analysis performed in a different system passed specifications and these results
were submitted in the report.
∗ Raw data and calculations were not checked by a second responsible individuals
required by your procedures. Inaccurate calculations were noted in the report.
∗ The process validation samples were assays using an HPLC method that had not been
validated. The method validation used for both products … did not include a protocol that included specification and acceptance criteria. … The method validation was not
reviewed and approved until during the current inspection. Lots of both products were released for distribution prior to completion of the method validation.
∗ Method validation for the product Sennosides is inadequate in that the data does not
Summary recommendations
∗
Develop a validation master plan or an operating procedure for method
validation
∗
For individual method validation projects, develop a validation project plan
∗
Define intended use of the method and performance criteria
∗
Check all equipment and material for performance and quality
∗
Perform validation experiments
∗
Summarize the Validation outcome (include the critical method validation
observations in the respective methods)
∗
Develop an operating procedure for method transfer between laboratories
Conclusions
Analytical Method Validation is not jus a “routine” activity.
Need to be done in a high level GMP environment
Results generated throughout the validation activity needs to be “reviewed carefully”
Successful validation provides – “Successful Method Transfers & Satisfactory
performance of the Analytical method throughout the Lifecycle”
Quality issues if not addressed during method validations may have severe impact during
drug development (loss of time, costs, regulatory queries etc.)
References
∗ ICH Q2 (R1) Validation of Analytical Procedures: Text and Methodology, International Conference on Harmonization.
∗ ICH Q3A (R2): Impurities in New Drug Substances, International Conference on Harmonization.
∗ ICH Q3B (R2): Impurities in New Drug Products, International Conference on Harmonization.
∗ ICH Q6A: Specifications: Test Procedures and Acceptance Criteria for New Drug Substances and New Drug Products: Chemical Substances, International Conference on Harmonization.
∗ ICH Q7: Good Manufacturing Practice Guidance for Active Pharmaceutical Ingredients, International Conference on Harmonization.
∗ FDA Draft Guidance for Industry on Analytical Procedures and Methods Validation: Chemistry, Manufacturing, and Controls Documentation. August 2000
∗ Center for Drug Evaluation and Research (CDER) Guidance: Guideline for Submitting Samples and Analytical Data for Methods Validation. February 1987
∗ Center for Drug Evaluation and Research (CDER) Reviewer Guidance: Validation of Chromatographic methods. November 1994
∗ US Pharmacopoeia General chapters: General tests and assays
∗ US Pharmacopoeia chapter <1225> Validation of Compendial Procedures
∗ US Pharmacopoeia chapter <1226> Verification of Compendial Procedures
∗ US Pharmacopoeia chapter <1092> The Dissolution Procedure: Development and Validation