COMMON PROBLEMS AND SOLUTIONS 2.6 COMMON PROBLEMS AND SOLUTIONS In the following pages we summarize some of the common deficiencies of potency method validation. These common problems are grouped together into categories such as HPLC instrumentation, procedural steps, and miscellaneous errors 2.6.1 HPLC Instrumentation Errors Qualification of Instruments. The status of the qualification of HPLC and other equipment used for the analytical procedure must always be checked. This is a common error that can lead to reanalysis of the samples if discovered earlier, repeating the entire experimental procedure if it was discovered after expiry of the sample solutions Vacuum Filtering of Mobile Phase. Vacuum filtering of the mobile phase should be avoided in a procedure that is very sensitive to the level of the organic in the mobile phase. Vacuum suction will evaporate the volatile organic portion during filtration(e. g, acetonitrile or methanol), and may lead to variation of the chromatography 2.6.2 Procedural errors Expiry of Mobile Phase. Always check the expiry of mobile phase before use This is one of the most common errors in an analytical laboratory Use of lon-Pairing Reagents in Mobile phase. It is usually recommended that if ion-pairing reagents are needed in a mobile phase, its concentration needs be constant during a gradient run. Changes in ion-pairing concentration during an hPLC run will increase the likelihood of chromatographic variation between runs(e. g, retention time drifts and quantitation precision). Quantitation of salts(e.g, Hydrochloride and Sodium Salt). The quantitative result that is reported from the analysis of salts is usually reported with reference to the base of the analyte. The scientist will need to remember to incorpora multiplier into the calculation to convert the salt data to the base data Stability of Standard and Sample Solutions. Appropriate stability of the standard and sample solutions will allow flexibility of the method to be used in a qual ity control laboratory. For example, 4-day stability of the standard and sample solutions will allow investigation if problems arise during a weekend HPLC run Dilution during Sample and Standard Preparation. Minimize the number of dilutions required to give the final dilutions of the sample and standard solutions Each dilution step will have the potential to introduce error in the procedure
COMMON PROBLEMS AND SOLUTIONS 23 2.6 COMMON PROBLEMS AND SOLUTIONS In the following pages we summarize some of the common deficiencies of potency method validation. These common problems are grouped together into categories such as HPLC instrumentation, procedural steps, and miscellaneous errors. 2.6.1 HPLC Instrumentation Errors Qualification of Instruments. The status of the qualification of HPLC and other equipment used for the analytical procedure must always be checked. This is a common error that can lead to reanalysis of the samples if discovered earlier, or repeating the entire experimental procedure if it was discovered after expiry of the sample solutions. Vacuum Filtering of Mobile Phase. Vacuum filtering of the mobile phase should be avoided in a procedure that is very sensitive to the level of the organic in the mobile phase. Vacuum suction will evaporate the volatile organic portion during filtration (e.g., acetonitrile or methanol), and may lead to variation of the chromatography. 2.6.2 Procedural Errors Expiry of Mobile Phase. Always check the expiry of mobile phase before use. This is one of the most common errors in an analytical laboratory. Use of Ion-Pairing Reagents in Mobile Phase. It is usually recommended that if ion-pairing reagents are needed in a mobile phase, its concentration needs to be constant during a gradient run. Changes in ion-pairing concentration during an HPLC run will increase the likelihood of chromatographic variation between runs (e.g., retention time drifts and quantitation precision). Quantitation of Salts (e.g., Hydrochloride and Sodium Salt). The quantitative result that is reported from the analysis of salts is usually reported with reference to the base of the analyte. The scientist will need to remember to incorporate a multiplier into the calculation to convert the salt data to the base data. Stability of Standard and Sample Solutions. Appropriate stability of the standard and sample solutions will allow flexibility of the method to be used in a quality control laboratory. For example, 4-day stability of the standard and sample solutions will allow investigation if problems arise during a weekend HPLC run. Dilution during Sample and Standard Preparation. Minimize the number of dilutions required to give the final dilutions of the sample and standard solutions. Each dilution step will have the potential to introduce error in the procedure
POTENCY METHOD VALIDATION Range in Validation of Linearity Is Smaller Than Precision and Accuracy. This error will invalidate the precision and accuracy data since the validation did not demonstrate the linearity of the analyte for the quantitation of precision and accuracy 2.6.3 Miscellaneous errors Validation Protocol. It is highly recommended to validate an analytical proce- dure using some form of validation protocol. Without a validation protocol, the scientist will have a tendency to vary the experiment during the course of the validation study. Getting into the habit of creating a validation protocol will also ensure that the scientist plans before starting the experiment Acceptance Criteria for Validation Parameter. It is highly recommended to set acceptance criteria prior to starting validation experiments. This will provide guidance to the validating scientist on the range of acceptability of the valida tion results Documentation of Observation. It is very important to document all relevant observations during the experimental procedure. Observations are the most impor- tant information that can be used if an investigation is needed Furthermore observations that are documented provide evidence in the event of patent chal- lenge and other court cases Absorbance of Analyte. It is common to devise an experimental procedure that yields an analyte absorbance value of less than I absorbance unit. A high absorbance value(depending on the absorptivity of the analyte)is the result of a high concentration of the analyte. Too high a concentration of the analyte may overload the column and lead to nonlinearity 2.7 SUMMARY OF POTENCY VALIDATION DATA It is very useful to summarize all method validation data into a tabular format The tabulated summary will give a quick overview of the validation data. Often, the analyst may be so involved during the actual validation work that some errors escaped detection. Table 2.7 is an example of how data can be recorded. Table 2.7. Sample Validation Summary ICH Validation Summary Characteristic Data Reported Validation Results Accuracy The percent recovery assessed Based on determinations at hree concentration levels determinations over a average recovery 101.490 RSD=0.9% concentration levels covering the range specified
24 POTENCY METHOD VALIDATION Range in Validation of Linearity Is Smaller Than Precision and Accuracy. This error will invalidate the precision and accuracy data since the validation did not demonstrate the linearity of the analyte for the quantitation of precision and accuracy data. 2.6.3 Miscellaneous Errors Validation Protocol. It is highly recommended to validate an analytical procedure using some form of validation protocol. Without a validation protocol, the scientist will have a tendency to vary the experiment during the course of the validation study. Getting into the habit of creating a validation protocol will also ensure that the scientist plans before starting the experiment. Acceptance Criteria for Validation Parameter. It is highly recommended to set acceptance criteria prior to starting validation experiments. This will provide guidance to the validating scientist on the range of acceptability of the validation results. Documentation of Observation. It is very important to document all relevant observations during the experimental procedure. Observations are the most important information that can be used if an investigation is needed. Furthermore, observations that are documented provide evidence in the event of patent challenge and other court cases. Absorbance of Analyte. It is common to devise an experimental procedure that yields an analyte absorbance value of less than 1 absorbance unit. A high absorbance value (depending on the absorptivity of the analyte) is the result of a high concentration of the analyte. Too high a concentration of the analyte may overload the column and lead to nonlinearity. 2.7 SUMMARY OF POTENCY VALIDATION DATA It is very useful to summarize all method validation data into a tabular format. The tabulated summary will give a quick overview of the validation data. Often, the analyst may be so involved during the actual validation work that some errors escaped detection. Table 2.7 is an example of how data can be recorded. Table 2.7. Sample Validation Summary ICH Validation Characteristic Data Reported Summary Validation Results Accuracy The percent recovery assessed using a minimum of nine determinations over a minimum of three concentration levels covering the range specified. Based on determinations at three concentration levels, average recovery = 101.4%, RSD = 0.9%
SUMMARY OF POTENCY VALIDATION DATA Table 2.7(continued) ICH Validation Characteristic Validation results Precision Repeatability The standard deviation, relative A single experiment(n =6 standard deviation (RSD) had a repeatability (RSD) of and confidence interval 1.1% should be reported for each type of precision Intermediate Based on experimental design (n 24)results from thI dosage strengths, the precision is 0.9%. producibility The average potency result obtained from the receiving laboratory is within t 0.5%o f results from the originating laboratory Representative chromatograms The placebo peaks, process demonstrate specificity. urte peaks are resolved from the Data from the regression Correlation Intercept sum of squares) and a plot. [area/(ug/mL)]; residual sum of squares= 178.96(e.g Procedure prov The range was confirmed as 70 acceptable degree of to 130%o of the test linearity, accuracy, and concentration en applied ithin or at the extremes of the specified range of (continued overleaf)
SUMMARY OF POTENCY VALIDATION DATA 25 Table 2.7 (continued) ICH Validation Characteristic Data Reported Summary Validation Results Precision Repeatability The standard deviation, relative standard deviation (RSD), and confidence interval should be reported for each type of precision investigated. A single experiment (n = 6) had a repeatability (RSD) of 1.1%. Intermediate Based on experimental design precision (n = 24) results from three dosage strengths, the estimated intermediate precision is 0.9%. Reproducibility The average potency result obtained from the receiving laboratory is within ± 0.5% of results from the originating laboratory. Specificity Representative chromatograms demonstrate specificity. The placebo peaks, process impurities, and degradant peaks are resolved from the peak of interest (e.g., Figure 2.4). Linearity Data from the regression line (correlation coefficient, y-intercept, slope, residual sum of squares) and a plot. Correlation coefficient = 0.9999; y-intercept = 0.0328 area unit; slope = 0.5877 [area/(µg/mL)]; residual sum of squares = 178.96 (e.g., data plot in Figure 2.2). Range Procedure provides an acceptable degree of linearity, accuracy, and precision when applied to samples containing analyte within or at the extremes of the specified range of procedure. The range was confirmed as 70 to 130% of the test concentration. (continued overleaf )
POTENCY METHOD VALIDATION Table 2.7(continued) ICH Validation Characteristic Validation results The factors evaluated(analy chromatography, typical instrument. %o aCn. and variations are: pH in a column age)did not have mobile phase, composition any significant effect of mobile phase, different (p >0.05)on the potency nd/or suppliers ), based on JMP analysis. The temperature, and flow rate method is robust for all the and sample solutions were found to be stable for 5 days REFERENCES 1. ICH Harmonized Tripartite Guideline, ICH Q2A, Text on Validation of Analytical Pro- cedures. Mar. 1995 2. CFR Part 211, Current Good Manufacturing Practice for Finished Pharmaceuticals 3. ICH Harmonized Tripartite Guideline, ICH Q2B, Validation of Analytical Procedures Methodology, May 1997. 4. ICH Harmonized Tripartite Guideline, ICH Q3B, Impurities in New Drug Products, Oct.1999 5. Drugs Directorate Guidelines: Health Protection Branch, Health Canada, Acceptable Methods. Ottawa. Ontario Canada. 1994 6. J. Essman et al., Int. Union Pure Appl. Chem. Anal. Chem. Div. 73(8), 1381-1386
26 POTENCY METHOD VALIDATION Table 2.7 (continued) ICH Validation Characteristic Data Reported Summary Validation Results Robustness In the case of liquid chromatography, typical variations are: pH in a mobile phase, composition of mobile phase, different columns (different lots and/or suppliers), temperature, and flow rate. The factors evaluated (analyst, instrument, % ACN, and column age) did not have any significant effect (p > 0.05) on the potency results in the ranges studied based on JMP analysis. The method is robust for all the factors studied. The standard and sample solutions were found to be stable for 5 days (at 30◦ C). REFERENCES 1. ICH Harmonized Tripartite Guideline, ICH Q2A, Text on Validation of Analytical Procedures, Mar. 1995. 2. CFR Part 211, Current Good Manufacturing Practice for Finished Pharmaceuticals. 3. ICH Harmonized Tripartite Guideline, ICH Q2B, Validation of Analytical Procedures: Methodology, May 1997. 4. ICH Harmonized Tripartite Guideline, ICH Q3B, Impurities in New Drug Products, Oct. 1999. 5. Drugs Directorate Guidelines: Health Protection Branch, Health Canada, Acceptable Methods, Ottawa, Ontario, Canada, 1994. 6. J. Vessman et al., Int. Union Pure Appl. Chem. Anal. Chem. Div. 73(8), 1381–1386, 2001
METHOD VALIDATION FOR HPLC ANALYSIS OF RELATED SUBSTANCES IN PHARMACEUTICAL DRUG PRODUCTS Y.C. LEE. PH. D Patheon y. Inc. 3.1 INTRODUCTIO In this chapter we outline the general requirements for analytical method valida tion for HPLC analysis of related substances in pharmaceutical products. Most of the discussion is based on method validation for pharmaceutical products of synthetic origin. Even though most of the requirements are similar for other types of pharmaceutical drug products(e.g, biopharmaceutical drug products), detailed discussion of method validation for other types of pharmaceutical drug products is outside the scope of this chapter. The discussion focuses on current regulatory juirements in the pharmaceutical industry. Since the expectations for method validation are different at different stages of the product development process. the information given in this chapter is most suitable for final method valida- tion according to the ICH requirements to prepare for regulatory submissions (e. g, NDA). Even though the method validation is related to HPLC analys most of the principles are also applicable to other analytical techniques(e.g TLC, UV) Analytical Method Validation and Instrument Performance Verification, Edited by Chung Chow IsBN 0-471-25953.5 Copyright o 2004 John Wiley Sons, Inc
3 METHOD VALIDATION FOR HPLC ANALYSIS OF RELATED SUBSTANCES IN PHARMACEUTICAL DRUG PRODUCTS Y. C. LEE, PH.D. Patheon YM, Inc. 3.1 INTRODUCTION In this chapter we outline the general requirements for analytical method validation for HPLC analysis of related substances in pharmaceutical products. Most of the discussion is based on method validation for pharmaceutical products of synthetic origin. Even though most of the requirements are similar for other types of pharmaceutical drug products (e.g., biopharmaceutical drug products), detailed discussion of method validation for other types of pharmaceutical drug products is outside the scope of this chapter. The discussion focuses on current regulatory requirements in the pharmaceutical industry. Since the expectations for method validation are different at different stages of the product development process, the information given in this chapter is most suitable for final method validation according to the ICH requirements to prepare for regulatory submissions (e.g., NDA). Even though the method validation is related to HPLC analysis, most of the principles are also applicable to other analytical techniques (e.g., TLC, UV). 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 Copyright 2004 John Wiley & Sons, Inc. 27