1. Dr. Birgit Schmauser, BfArM, Bonn
Verification of applicability of the validated/compendial API analytical method for the final formulation (assay, dissolution test and degradants)
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

2. Dr. Birgit Schmauser, BfArM, Bonn
Guidelines
ICH Q2A
Validation of Analytical Methods: Definitions and Terminology (CPMP/ICH/381/95)
ICH Q2B
Validation of Analytical Procedures: Methodology (CPMP/ICH/281/95)
ICH Q6A
Specifications: Test Procedures and Acceptance Criteria for New Drug Substances and New Drug Products: Chemical Substances (CPMP/ICH/367/96 corr)
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

3. Dr. Birgit Schmauser, BfArM, Bonn
API
Assay
Validation with respect to:
Specificity, linearity/range, accuracy, precision, robustness
Impurities
Specificity, linearity/range, accuracy, precision, limit of detection (LOD), limit of quantitation (LOQ), robustness
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

4. Dr. Birgit Schmauser, BfArM, Bonn
FPP
New situation arising from the formulation of the drug product
Presence of further APIs
Presence of excipients (individual formulation)
Presence of known impurities/degradants of all APIs and potential new degradants or incompatibility products
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

5. Dr. Birgit Schmauser, BfArM, Bonn
Requirements
Capability of the analytical method(s):
Assay of each API in the presence of the other APIs and all impurities/degradants
Assay of each degradant in the presence of all APIs and all other degradants/impurities
Influence of formulation components should be excluded/controlled
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

6. Dr. Birgit Schmauser, BfArM, Bonn
Revalidation I
Revalidation of analytical methods with respect to:
Specificity
presence of new API(s) and impurities/degradants/formulation components
Range
test concentrations of API(s) versus FPP
Accuracy
influence of formulation components
Precision
influence of formulation and sample preparation
LOD/LOQ
test concentrations of API(s) versus FPP)
Robustness
change of column material, column parameters, solvents)
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

7. Dr. Birgit Schmauser, BfArM, Bonn
Revalidation II
Revalidation reflected by ICH Q2A:
Revalidation may be necessary in the following circumstances:
Changes in the synthesis of the drug substance
Changes in the composition of the finished product
Changes in the analytical procedure
(e.g. robustness)
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

8. Dr. Birgit Schmauser, BfArM, Bonn
Specificity
Identification
Discrimination between compounds of closely related structures
positive results (from samples containing the analyte)
negative results (from samples that do not contain the analyte)
components structurally similar to the analyte do not give positive results
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

9. Dr. Birgit Schmauser, BfArM, Bonn
Specificity II
Assay and impurities
Chromatographic procedures
Representative chromatograms with appropriate labelling of individual components
Investigation at an appropriate level
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

10. Dr. Birgit Schmauser, BfArM, Bonn
Specificity III
Assay and impurities/degradants
Discrimination of analytes where impurities/degradants are available
Assay
Demonstration of discrimination of the analyte in the presence of all impurities/degradants and/or excipients
f. ex. assay result unaffected by presence of spiked impurities/degradants
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

11. Dr. Birgit Schmauser, BfArM, Bonn
Specificity IV
Assay and impurities/degradants
Discrimination of analytes where impurities/degradants are available
Impurities/Degradants
Demonstration of separation of impurities/degradants individually and/or from excipients
f. ex. spiking of API with appropriate levels of impurities/degradants and/or excipients
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

12. Dr. Birgit Schmauser, BfArM, Bonn
Specificity V
Assay and impurities/degradants
Discrimination of analytes where impurities/degradants are not available
Comparison of the test procedure to a second well-characterized (independent) procedure
Samples
Test samples containing impurities/degradants
Test samples stored under relevant stress conditions (potential degradants arising during shelf life)
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

13. Dr. Birgit Schmauser, BfArM, Bonn
Specificity VI
Assay and impurities/degradants
Discrimination of analytes where impurities/degradants are not available
Assay
Comparison of test results by the two independent procedures
Impurities/Degradants
Comparison of impurity profiles
Peak purity assessment
Demonstration that the analyte peak is attributable to only one component
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

14. Dr. Birgit Schmauser, BfArM, Bonn
Example
FDC (artesunate and amodiaquine)
One analytical method for both APIs
Capability of one method to quantify both APIs and to separate/discriminate the other API and its impurities/degradants and potential incompatibility products from the existing API and its impurities/degradants
Some reference material for impurities/degradants will be available (spiking experiments applicable)
Other degradants are not available as reference material (stress testing necessary to generate in situ degradants)
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

15. Dr. Birgit Schmauser, BfArM, Bonn
Range
Minimum specified ranges
Assay
80 – 120% of the test concentration
Content uniformity
70 – 130% of the test concentration
Dissolution
Q-20% - 120%
Impurities/Degradants
Reporting level to 120% of specification limit
Revalidation is necessary, if the ranges covered during validation of the API-methods are different from those of the FPP-methods (different test concentrations)
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

16. Dr. Birgit Schmauser, BfArM, Bonn
Accuracy
Assay
Application of the analytical procedure to synthetic mixtures of the product components (placebo mixture) to which known quantities of the analyte have been added
In case certain product components are unavailable:
Application of the analytical procedure to the product to which known quantities of the analyte have been added
Comparison of results obtained by a second (independent) procedure with defined accuracy
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

17. Dr. Birgit Schmauser, BfArM, Bonn
Accuracy II
Impurities/Degradants
Assessment of samples spiked with known amounts of impurities/degradants
In case certain impurities/degradation products are unavailable
Comparison of results obtained by a second (independent) procedure with defined accuracy
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

18. Dr. Birgit Schmauser, BfArM, Bonn
Precision
Assay and impurities/degradants
Repeatability
9 determinations (3 x 3) covering the specified range or
6 determinations at 100% of the test concentration
Intermediate precision
Effects of random events on the precision of the procedure, e.g.
Days
Analysts
Equipment
To be performed with a test solution prepared from the drug product
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

19. Dr. Birgit Schmauser, BfArM, Bonn
Detection Limit
Determination based on
Visual evaluation (non-instrumental and instrumental methods)
Signal to Noise (baseline noise)
Standard deviation of response (s) and slope (S)
DL=3.3s/S
Estimation of S
from the calibration curve of the analyte
Estimation of s
from the standard deviation of the blank
from the standard deviation (regression line or y-intercept) of a calibration curve in the range of the DL
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

20. Dr. Birgit Schmauser, BfArM, Bonn
Quantitation Limit
Determination based on
Visual evaluation (non-instrumental and instrumental methods)
Signal to Noise (baseline noise)
Standard deviation of response (s) and slope (S)
QL=10s/S
Estimation of S
from the calibration curve of the analyte
Estimation of s
from the standard deviation of the blank
from the standard deviation (regression line or y-intercept) of a calibration curve in the range of the QL
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

21. Dr. Birgit Schmauser, BfArM, Bonn
Robustness I
Reliability of an analysis with respect to deliberate variations in method parameters
Susceptibility to variations in analytical conditions?
control of analytical conditions or precautionary statement
establishment of system suitability parameters
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

22. Dr. Birgit Schmauser, BfArM, Bonn
Robustness II
Examples of variations
Stability of analytical solutions
Extraction time
In the case of liquid chromatography
Influence of variations of pH in a mobile phase
Influence of variations in mobile phase composition
Influence of columns (different lots and/or suppliers)
Influence of temperature
Influence of flow rate
In the case of gas chromatography
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

23. Dr. Birgit Schmauser, BfArM, Bonn
Dissolution
Applicability of the analytical method used for assay and impurities/degradants
Sample preparation
Range
Applicability of the dissolution method
Appropriateness of drug release acceptance criteria
Solubility criteria of the APIs
Appropriateness of test conditions and acceptance criteria
Dissolution affecting bioavailability
Changes in formulation or manufacturing variables affecting dissolution
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

24. Dr. Birgit Schmauser, BfArM, Bonn
Dissolution II
Applicability of the analytical method used for assay and impurities/degradants
Potential parameters for revalidation
Sample preparation
Stability of analytes in the dissolution medium?
Preparation of an injectable sample volume according to the analytical method?
Precision of analysis of the prepared dissolution sample?
Range of test concentrations of API / impurities / degradants according to the validated ranges?
Test concentration of prepared dissolution sample versus test concentration of FPP sample
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

25. Dr. Birgit Schmauser, BfArM, Bonn
Dissolution III
Applicability of the dissolution method
Appropriateness of drug release acceptance criteria
Solubility of the APIs (ICH Q6A Definitions)
Rapidly dissolving products
Not less than 80% of the label amount of the drug substance dissolves within 15 minutes in each of the following media: pH 1.2, pH 4.0, pH 6.8
Highly water soluble drugs
Drugs with a dose/solubility volume of less than or equal to 250 ml over a pH range of 1.2 to 6.8
Low solubility drugs
Drugs with a dose/solubility volume of more than 250 ml
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

26. Dr. Birgit Schmauser, BfArM, Bonn
Dissolution IV
Appropriateness of drug release acceptance criteria
Solubility of the APIs
Problem with low solubility drugs:
Solution of the drugs may become a time-limiting step
Dissolution also dependent on the strength of the drug product
Dissolution test cannot reflect batch to batch consistency
Possible solution of the problem
Extending the dissolution volume beyond the time-limiting volume
Validation of the dissolution procedure with extended volume (applicability of the pharmacopoeial procedure)
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

27. Dr. Birgit Schmauser, BfArM, Bonn
Dissolution V
Applicability of the dissolution method
Appropriateness of test conditions and acceptance criteria (ICH Q6A)
Dissolution significantly affecting bioavailability
Have relevant developmental batches exhibited unacceptable bioavailability?
Development of test conditions and acceptance criteria which can distinguish batches with unacceptable bioavailability
Changes in formulation or manufacturing variables affecting dissolution
Control of these changes by another procedure and acceptance criterion or
Development of test conditions and acceptance criteria which can distinguish these changes
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

28. Deficiencies from prequalification
Validation of precision
Precision of the drug substance solution lower than precision of the drug product solution
Acceptance criteria for precision of the drug substance solution wider than for precision of the drug product solution
Acceptance criteria much wider than real values assessed
Acceptance criteria of assay specifications and precision do not match
(3 x RSD outside the specification range)
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

29. Deficiencies from prequalification II
Assay of API and impurities/degradants
No acceptable mass balance found between assay of API and impurities/degradants
Quantitation limit of impurities too high
ICH requirement on threshold for identification and qualification of unknown impurities cannot be fulfilled
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn

30. Deficiencies from prequalification III
Dissolution
Necessary information on development of dissolution test not presented
Dissolution method (pharmacopoeial) not presented along with development of dissolution test and/or validation of applicability of analytical methods
Test conditions and acceptance criteria of the dissolution test not justified
Guilin, January, 9 – 13, 2006
Dr. Birgit Schmauser, BfArM, Bonn