Pharmaceutical Development with Focus on Paediatric formulations

1. Pharmaceutical Development with Focus on Paediatric formulations WHO/FIP Training Workshop Hyatt Regency Hotel Sahar Airport Road Andheri East, Mumbai, India 28 April 2008 – 2 May 2008

2. Analytical Method Development Presented by: Birgit Schmauser, PhD Federal Institute for Drugs and Medical Devices (BfArM) b.schmauser@bfarm.de

3. Analytical Method Development In this presentation: • Standards in developing analytical methods for • Originator and multisource generic FPPs • Specifications • Stability • Parallel development of analytical methods for cleaning validation

4. Analytical Method Development Originator, First-timeGeneric and Multisource Generic

5. Analytical Method Development • HPLC-method to assay potency and purity – risk assessment

6. Analytical Method Development Interchangeability (IC) of multisource generic FPPs (Essential similarity with Innovator FPP) Pharmaceutical + BioequivalenceEquivalence IC = PE + BE

7. Analytical Method Development • Pharmaceutical equivalence • FPPs meet the same or comparable standards by use of equivalent analytical methods • Same API (chemical and physical equivalence) • Same dosage form and route of administration • Same strength • Comparable labeling • Equivalence in pharmaceutical development • Equivalence in stability • Equivalence in manufacture (WHO-GMP)

8. Analytical Method Development • Prequalification requirements • Validation of analytical methods is a prerequisite for prequalification of product dossiers • Non-compendial APIs and FPPs are tested with methods developed by the manufacturer • For compendial APIs and FPPs the „applicability“ of pharmacopoeial methodsto particular products must be demonstrated (verification) • Analytical methods must be developed and validated according to TRS 823, Annex 5, Validation of analytical procedures used in the examination of pharmaceutical materials; ICH Q2 (R1) • To be used within GLP and GMP environments

9. Analytical Method Development Use of analytical methods - generics

10. Analytical Method Development Machine Man Methods calibrated qualified characterised documented robust suitable skilled qualified Quality of theanalytical method Referencestandards Vibrations Time Analysts´support Irradi-ations Tempe-rature Supplies Humidity Quality Material Milieu Management • Prerequisites for analytical method validation • Six “M”s

11. Analytical Method Development Method development Initital Method Development Development Plan –Project Pre-Validation Evaluation Method Optimization Robustness System Suitability Customer EvaluationTesting Validation Experiments PeriodicallyMonitoring/Reviewof Methodsin Control Labs Method TransferExperiments Filed Method in Use • Method development life cycle Planning Development and Validation Policy Objectives/Requirements of Method Information Gathering Resource Gathering From: Analytical Chemistry in a GMP Environment. Edited by J.M. Miller and J.B. Crowther, ISBN 0-471-31431-5, Wiley & Sons Inc.

12. Analytical Method Development • Validation should verify the suitability of an analytical method for its intended purpose • Validation should be founded on method development performed beforehand that suggest thesuitability and robustness of the method • Validation may be performed in different ways (individual purpose) according to common standards

13. Validation protocol • Method principle / objective • Listing of responsibilities • Laboratories involved and their role in the validation • Method categorization • List of reagents (including test lots) and standards • Test procedures to evaluate each validation parameter and proposed acceptance criteria • Plan or procedure when acceptance criteria are not met • Requirements for the final report • The validation process cannot proceed until the protocol and all parties involved approve the acceptance criteria

14. Analytical Method Development • Innovator versus Generics

15. Analytical Method Development • Validation Characteristics

16. Analytical Method Development • Accuracy and precision Accurate & precise Accurate & imprecise Inaccurate & precise Inaccurate & imprecise

17. Analytical Method Development • Precision • Expresses the closeness of agreement between a series of measurements obtained from multiple sampling of the same homogenous sample • Is usually expressed as the standard deviation (S),variance(S2) or coefficient of variation(RSD) of a series of measurements • Precision may be considered at three levels • Repeatability(intra-assay precision) • Intermediate Precision(variability within a laboratory) • Reproducibility(precision between laboratories)

18. Analytical Method Development • Normal distribution, probability function [P(x)]and confidence interval [CI] • Probability (P), that measurements from a normal distribution fall within [µ-xn, µ+xn] for xn = ns is described by the “erf-function” (µ= mean): • An interval of ± 3 scovers 99.73% of values Number of times each value occurs s s Values 2s 2s 3s 3s

19. Analytical Method Development • Normal distribution, probability function [P(x)] and confidence interval [CI] • Probability-P Confidence interval [CI]centered around the mean [µ]in units of sigma [s] described by“inverse erf-function”: • A CI of 95% includes values± 1.95 s around the mean

20. Analytical Method Development • Relationship of variability, probability and reliability of data • High variability of data (large s) generate large confidence intervals and thus lower the reliability of the mean • Low variability of data (small s) generate small confidence intervals and thus increase the reliability of the mean

21. Analytical Method Development • Repeatability • Six replicate sample preparation steps from a homogenously prepared tablet mixture (nominal value of API 150 mg) Mean ± 3 SD =Confidence interval of 99.73% 98.96 ± 3x1.32% = 95% - 102.92%

22. Analytical Method Development • Intermediate precision • Expresses within-laboratories variations (different days, different analysts, different equipment etc.) Mean ± 3 SD: (177252  100%) Analyst 1: 98.96% ± 3 x 1.32% Analyst 2: 99.12% ± 3 x 0.28 Analyst 3: 100.70% ± 3 x 0.51 Average of 3 analysts ± 3SD:95% - 102.23%

23. Analytical Method Development • Reproducibility • Expresses the precision between laboratories • Collaborative studies, usually applied to standardisation of methodology • Transfer of technology • Compendial methods

24. Analytical Method Development mean true • Accuracy • Expresses the closeness of agreementbetween the value which is accepted either as a conventional true valueor an accepted reference value and the value found • Sometimes referred to as „TRUENESS“

25. Analytical Method Development To find out whether a method is accurate: • Drug substance (assay) • Application of the method to an analyte of known purity (e.g. reference substance) • Comparison of the results of one method with those of a second well-characterised method (accuracy known) • Drug product (assay) • Application of the method to synthetic mixtures of the drug product component to which known quantities of the analyte have been added • Drug product may exceptionally be used as matrix • Drug substance/Drug product (Impurities) • Application of the method to samples spiked with known amounts of impurities

26. Analytical Method Development • Accuracy: Application of the method to synthetic mixtures of the drug product componentsto which known quantitiesof the analytehave been added • Recovery reducedby ~10 – 15% From: Analytical Method Validation and Instrument Performance Verification, Edited by Chung Chow Chan,Herman Lam, Y.C. Lee and Xue-Ming Zhang, ISBN 0-471-25953-5, Wiley & Sons

27. Analytical Method Development • When to expect Accuracy problems • Insufficient selectivity of the method • Impurity peaks are not resolved and account for assay value • Recovery is < 100% • Irreversible adsorption of analyte to surfaces of the system • Incorrect assay value of a reference standard • Due to decomposition of reference standard • Incorrect assay value due to change in matrix • Analytical laboratory still uses the preceding matrix as standard

28. Analytical Method Development • Specificity • Is the ability to assess unequivocally the analyte in the presence of components which may be expected to be present (impurities, degradants, matrix…) • Identity testing • To ensure the identity of an analyte • Purity testing • To ensure accurate statement on the content of impurities of an analyte • Assay • To allow an accurate statement on the content of an analyte in a sample

29. Analytical Method Development • Specificity:Overlay chromatogram of an impurity solution with a sample solution From: Analytical Method Validation and Instrument Performance Verification, Edited by Chung Chow Chan,Herman Lam, Y.C. Lee and Xue-Ming Zhang, ISBN 0-471-25953-5, Wiley & Sons

30. Analytical Method Development Specificity and stability • Stress stability testing to ensure the stability indicating potential of an analytical method • Apply diverse stress factors to the API • Apply diverse stress factors to the FPP • Stress conditions: e.g. Supplement 2 of Generic Guideline; TRS 929, Annex 5 • Assure that the API can be assessed specifically in the presence of known and unknown (generated by stress) impurities • Assure that known impurities/degradants can be specifically assessed in the presence of further degradants • By peak purity assessment and (overlay of) chromatograms

31. Analytical Method Development • Stress stability studies versus forced degradation studies

32. Analytical Method Development • Limit of Detection (LOD, DL) • The LOD of an analytical procedure is the lowest amount of analyte in sample which can be detected but not necessarily quantitated as an exact value • Determination is usually based on • Signal to noise ratio (~3:1) (baseline noise) or • Standard deviation of response (s) and Slope (S) • 3.3 s/S

33. Analytical Method Development • Limit of Quantitation (LOQ, QL) • The LOQ is the lowest amount of analyte in a sample which can be quantitatively determined with suitable precision and accuracy • The quantitation limit is used particularly for the determination of impurities and/or degradation products • Determination is usually based on • Signal to noise ratio (~10:1) (baseline noise) or • Standard deviation of response (s) and Slope (S) • 10 s/S

34. Analytical Method Development LOD, LOQ and Signal to Noise Ratio (SNR) LOQ Signal to Noise = 10:1 LOD Signal to Noise = 3:1 Noise

35. Analytical Method Development • LOQ • Quantitation by SNR is accepted • Quantitation by Standard deviation of response (s) and Slope (S) (10 s/S) is more adequate as it involves the response of the actual analyte • Best to calculate in the region close to y-intercept

36. Analytical Method Development • LOQ and impurities • In determination of impurities in APIs and FPPs the LOQ should be determined in the presence of API • LOQ should be NMT reporting level • LOQ should be given relative to the test concentration of API • Specificity of impurity determination should always be demonstrated in the presence of API at API specification levels • Spiking of test concentration (API/FPP) with impurities at levels of their specification range

37. Analytical Method Development • Spiking • API test concentration (normalised) • 0.1 mg/ml (100%) • Impurity spiking concentrations • 0.001 mg/ml (1%) – specification limit • 0.0001 mg/ml (0.1%) – limit of quantitation (minimum requirement) API at test concentrations API below test concentrations

38. Analytical Method Development • Linearityof an analytical procedure is its ability (within a givenrange) to obtain test resultswhich are directly proportional to the concentration (amount) of analyte in the sample • If there is a linear relationship test results should be evaluatedby appropriate statistical methods • Correlation coefficient (r) • Y-intercept • Slope of regression line • Residual sum of squares • PLOT OF THE DATA

39. Analytical Method Development • Usual acceptance criteria for a linear calibration curve • r > 0.999; y-intercept a < 0 to 5% of target concentrationRSD (wrt calibration curve) < 1.5-2% r > 0.997 r < 0.997 From: Analytical Method Validation and Instrument Performance Verification, Edited by Chung Chow Chan,Herman Lam, Y.C. Lee andXue-Ming Zhang, ISBN 0-471-25953-5, Wiley & Sons

40. Analytical Method Development • Range • The range of an analytical procedure is the interval between the upper and lower concentration (amounts) of analyte in the sample for which it has been demonstrated that the analytical procedure has a suitable level of precision, accuracy and linearity

41. Analytical Method Development • Range • Assay • 80 to 120% of test concentration • Content uniformity • 70 to 130% of test concentration • Dissolution • Q-20% to 120% • Impurities • Reporting level – 120% of specification limit (with respect to test concentration of API) • Assay & Impurities • Reporting level to 120% of assay specification

42. Analytical Method Development • Linearity is limited to 150%of shelf life specification of impurities • Test concentration can beused to determine impurities • To determine drug substance(assay) the test concentrationmust be diluted • The range is 0 – ~ 150% ofimpurity specification From: Analytical Method Validation and Instrument Performance Verification, Edited by Chung Chow Chan,Herman Lam, Y.C. Lee and Xue-Ming Zhang, ISBN 0-471-25953-5, Wiley & Sons

43. Analytical Method Development • Robustness • Robustness of an analytical procedure should show the reliabilityof an analysis with respect to deliberate variations in method parameters • The evaluation of robustness should be considered during the development phase • 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

44. Analytical Method Development • Influence of buffer pH and buffer concentration in mobile phase on retention times of API and impurities • Conclusion: The buffer composition should be maintained in a range of 85 ± 0.5% • Missing: Acceptance criterion for maximal deviation of retention time should be defined unless justified

45. Analytical Method Development • System suitability testing • Based on the concept that equipment, electronics, analytical operations and samples to be analysed constitute an integral system that can be evaluated as such • Suitability parameters are established for each analytical procedureindividually • Depend on the type of analytical procedure

46. Analytical Method Development • Method stability • System suitability over time • Sample solution stability • A solution of stavudine is stable for ~ 2 h, then it starts to degrade to thymine • Impurity-spiked sample solution stability • A solution containing stavudine spiked with its impurity thyminedoes not allow to clearly distinguish between degradation and spike • A solution containing stavudine of a FPP-stability sample solution does not allow to clearly distinguish between FPP-stability degradation and sample solution degradation • Should be analysed immediately

47. Analytical Method Development • When to be „surprised“ about validation data: • Precision ofimpurity determination • Precision ofAPI determination • Method precision ofreleased API (dissolution)

48. Analytical Method Development • Specification range (USL-LSL) • Process variability (usually ± 2 SD) • Analytical variability (± 3s) • ~ NMT 30% of total specification range • Analytical variabilityProcess variability • Reliability of evaluation of major process variables by analytical procedures depends on analytical variability • Impurities • LOQ and specification limit (e.g. qualification limits NMT 0.15%) • Response factors (LOQ modified by response factor)

49. Analytical Method Development • Methods for cleaning validation • Method for assay and related substances used in stability studies of API and FPP • Specificity (in samples taken from a cleaning assessment) • Linearity of response (from 50% of the cleaning limit to 10x this concentration; R2≥0.9900) • Precision • Repeatability (RSD ≤5%) • intermediate precision [ruggedness (USP)] • Reproducibility • Limits of detection and quantitation • Accuracy or recovery from rinsate (≥80%), swabs (≥90%), and process surface (≥ 70%) • Range (lowest level is at least 2x higher than LOQ)

50. Analytical Method Development Summary • Analytical procedures play a critical role in pharmaceutical equivalence and risk assessment/management • Establishment of product-specificacceptance criteria • Assessment of stability of APIs and FPPs • Validation of analytical procedures should demonstrate that they are suitable for their intended use • Validation of analytical procedures deserves special attention during assessmentof dossiers for prequalification