Verification of applicability of the validated/compendial API analytical method for the final formulation (assay, dissol

1. Verification of applicability of the validated/compendialAPI analytical methodfor the final formulation(assay, dissolution test and degradants) Dr. Birgit Schmauser, BfArM, Bonn

2. 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) Dr. Birgit Schmauser, BfArM, Bonn

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

4. 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 Dr. Birgit Schmauser, BfArM, Bonn

5. 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 Dr. Birgit Schmauser, BfArM, Bonn

6. 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) Dr. Birgit Schmauser, BfArM, Bonn

7. 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) Dr. Birgit Schmauser, BfArM, Bonn

8. 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 Dr. Birgit Schmauser, BfArM, Bonn

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

10. 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 Dr. Birgit Schmauser, BfArM, Bonn

11. 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 Dr. Birgit Schmauser, BfArM, Bonn

12. 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) Dr. Birgit Schmauser, BfArM, Bonn

13. 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 Dr. Birgit Schmauser, BfArM, Bonn

14. 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) Dr. Birgit Schmauser, BfArM, Bonn

15. 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) Dr. Birgit Schmauser, BfArM, Bonn

16. 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 Dr. Birgit Schmauser, BfArM, Bonn

17. 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 Dr. Birgit Schmauser, BfArM, Bonn

18. Precision • Assay and impurities/degradants • Repeatability • 9 determinations (3 x 3) covering the specified rangeor • 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 Dr. Birgit Schmauser, BfArM, Bonn

19. Detection Limit • Determination based on • Visual evaluation (non-instrumental and instrumental methods) • Signal to Noise (baseline noise) • Standard deviation of response (s) andslope (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 Dr. Birgit Schmauser, BfArM, Bonn

20. Quantitation Limit • Determination based on • Visual evaluation (non-instrumental and instrumental methods) • Signal to Noise (baseline noise) • Standard deviation of response (s) andslope (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 Dr. Birgit Schmauser, BfArM, Bonn

21. Robustness I • Reliability of an analysis with respect to deliberate variations in method parameters • Susceptibility to variations in analytical conditions? • control of analytical conditionsorprecautionary statement • establishment of system suitability parameters Dr. Birgit Schmauser, BfArM, Bonn

22. 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 • Influence of columns (different lots and/or suppliers) • Influence of temperature • Influence of flow rate Dr. Birgit Schmauser, BfArM, Bonn

23. Dissolution • Applicability of the analytical method used for assay and impurities/degradants • Sample preparation • Range • Applicability of the dissolution method • Appropriateness of drug releaseacceptance criteria • Solubility criteria of the APIs • Appropriateness of test conditionsandacceptance criteria • Dissolution affecting bioavailability • Changes in formulation or manufacturing variables affecting dissolution Dr. Birgit Schmauser, BfArM, Bonn

24. 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 Dr. Birgit Schmauser, BfArM, Bonn

25. 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 than250 ml Dr. Birgit Schmauser, BfArM, Bonn

26. 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) Dr. Birgit Schmauser, BfArM, Bonn

27. 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 criterionor • Development of test conditions and acceptance criteria which can distinguish these changes 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) 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 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 Dr. Birgit Schmauser, BfArM, Bonn