A Practical Approach to Validation of HPLC Methods Under Current Good Manufacturing Practices

Analytical methods validation is an important regulatory requirement in pharmaceutical analysis. Performance Liquid Chromatography (HPLC) is commonly used as an analytical technique in developing and validating assay methods for drug products and drug substances. Method validation provides documented evidence, and a high degree of assurance, that an analytical method employed for a specific test, is suitable for its intended use. Over recent years, regulatory authorities have become increasingly aware of the necessity of ensuring that the data submitted to them in applications for marketing authorizations have been acquired using validated analytical methodology. The International Conference on Harmonization (ICH) has introduced guidelines for analytical methods validation. 1,2 The U.S. Food and Drug Administration (FDA) methods validation draft guidance document, 3-5 as well as United States Pharmacopoeia (USP) both refer to ICH guidelines. These draft guidances define regulatory and alternative analytical procedures and stability-indicating assays. The FDA has proposed adding section CFR 211.222 on analytical methods validation to the current Good Manufacturing Practice (cGMP) regulations. 7 This would require pharmaceutical manufacturers to establish and document the accuracy, sensitivity, specificity, reproducibility, and any other attribute (e.g., system suitability, stability of solutions) necessary to validate test methods. Regulatory analytical procedures are of two types: compendial and noncompendial. The noncompendial analytical procedures in the USP are those legally recognized as regulatory procedures under section 501(b) of the Federal Food, Drug and Cosmetic Act. When using USP analytical methods, the guidance recommends that information be provided for the following characteristics: specificity of the method, stability of the analytical sample solution, and intermediate precision. Compendial analytical methods may not be stability indicating, and this concern must be addressed when developing a drug product specification, because formulation based interference may not be considered in the monograph specifications. Additional analytical tests for impurities may be necessary to support the quality of the drug substance or drug product. Noncompendial analytical methods must be fully validated. The most widely applied validation characteristics are accuracy, precision (repeatability and intermediate precision), specificity, detection limit, quantitation limit, linearity, range, and stability of analytical solutions. The parameters that require validation and the approach adopted for each particular case are dependent on the type and applications of the method. Before undertaking the task of method validation, it is necessary that the analytical system itself is adequately designed, maintained, calibrated, and validated. 8 The first step in method validation is to prepare a protocol, preferably written with the instructions in a clear step-by-step format. This A Practical Approach to Validation of HPLC Methods Under Current Good Manufacturing Practices