Analytical method validation reliability

Reliable residue data are generated during the development of an a.i. to support the assessment of the consumer risk (residue data and toxicological data) and the impact on the environment (fate and behavior, efficacy and ecotoxicological data). It is critical that these analytical methods are reliably validated. In the guidance document SANCO/3029/99 rev. 4 (11/07/00), harmonized requirements for the residue analytical method are described. Validated analytical methods are required for the following studies ... 

The error of an analytical result is related to the (in)accuracy of an analytical method and consists of a systematic component and a random component [14]. Precision and bias studies form the basis for evaluation of the accuracy of an analytical method [18]. The accuracy of results only relates to the fitness for purpose of an analytical system assessed by method validation. Reliability of results however has to do with more than method validation alone. MU is more than just a singlefigure expression of accuracy. It covers all sources of errors which are relevant for all analyte concentration levels. MU is a key indicator of both fitness for purpose and reliability of results, binding together the ideas of fitness for purpose and quality control (QC) and thus covering the whole QA system [4,37]. 

Analytical methods validation is one of the most regulated validation processes in the pharmaceutical industry. Analytical validations are required to demonstrate that the methods employed are the most indicated for each product and that the results obtained are reliably correct. All methods employed in raw and finished product materials analysis are required to be validated. 

Like all models, there are underlying assumptions. The main ones for analytical method validation include the areas of equipment qualification and the integrity of the calibration model chosen. If the raw analytical data are produced by equipment that has not been calibrated or not shown to perform reliably under the conditions of use, measurement integrity may be severely compromised. Equally, if the calibration model and its associated calculation methods chosen do not adequately describe the data generated then it is inappropriate to use it. These two areas are considered in some detail in Chapter 8. 

Analytical method validation—Aprerequisite for any validation involving the analysis of the microbiological, physical, or chemical aspects of materials is the use of analytical methods that have been demonstrated to be reliable and reproducible. No meaningful assessment of product or material quality can be made without the... 

An analytical method is a laboratory procedure that measures an attribute of a raw material, drug substance, or a drug product. Analytical method validation is the process of demonstrating that an analytical method is reliable and adequate for its intended purpose. Any method that is utilized to determine results during drug substance and formulation development will have to be validated. Reliable data for release of clinical supplies, stability, and setting shelf life can only be generated with appropriate validated methods. 

To the pharmaceutical world, the meaning of analytical methods validation is the process to confirm that a method does what it purports to do, that is, to document through laboratory studies that the measurement procedure can reliably assess the identity, strength, and/or quality of a bulk drug substance, excipient, or finished pharmaceutical product. To provide consistent, worldwide regulatory expectations, previously unavailable, the International Conference on Harmonization has defined the methods validation... 

Method validation is covered in the current Good Manufacturing Practices (cGMPs) under section 211.165(e) which indicates that The accuracy, sensitivity, specificity, and reproducibility of tests methods. .. shall be established and documented . Such validation and documentation may be accomplished in accordance with 211.194(a) (2) which includes the need to indicate the location of data that establish that the methods used in the testing of the sample meet proper standards of accuracy and reliability as applied to the product tested . Methods included in recognized standard references such as the current USP/NF are understood to be validated. The suitability of all testing methods used shall be verified under actual conditions of use (211.194). For new products for which methods are developed, analytical method validation as described in this chapter will be necessary for methods already included in the USP, method verification will suffice. 

LGC - VAM Publications (i) The Fitness for Purpose of Analytical Methods, A Laboratory Guide to Method Validation and Related Topics, (2) Practical Statistics for the Analytical Scientist A Bench Guide By TJ Farrant, (3) Trace Analysis A structured Approach to Obtaining Reliable Results By E Pritchard, (4) Quantifying Uncertainty in Analytical Measurement, and (5) Quality in the Analytical Chemistry Laboratory. LGC/RSC Publications, London, England. 

Established in 1894, AOAC International is an independent association of scientists and organizations in the public and private sectors devoted to promoting methods validation and quality measurements in the analytical sciences. AOAC has a mission to ensure the development, testing, validation, and publication of reliable chemical and biological methods of analysis for foods, drugs, feed-stuffs, fertilizers, pesticides, water, forensic materials and other substances affecting public health and safety and the environment. 

Finally, it is important to define the lowest level of method validation (LLMV). The LLMV is defined as the lowest concentration level expressed in terms of amount of analyte in the matrix, at which the method (extraction/analysis procedure) was validated or proven to be capable of reliably quantifying. 

Consistent with other analytical methods, immunoassays must be validated to ensure that assay results are accurate. Initial validation involves an evaluation of the sensitivity and specificity of the immunoassay, while later validation includes comparison with a reference method. Because a goal of immunoassays is to minimize sample preparation, validation also includes testing the effects of sample matrices and(or) sample cleanup methods on results. The final steps in validation involve testing a limited number of samples containing incurred residues to determine if the method provides reliable data. 

Method validation is needed to demonstrate the acceptability of the analytical method. A recovery test on a chemical being determined should be performed in order to verify the reliability of the series of analyses. Recovery studies are usually conducted by spiking untreated sediment with the target chemical at the deteetion limit, quantitation limit and in the range of 10-50 times the detection limit. The method is considered acceptable when the recoveries typically are greater than 70%. When the recovery is less than 70%, an improvement in the analytical methods is needed. Where this is not possible for technical reasons, then lower recovery levels may be acceptable provided that method validation has demonstrated that reproducible recoveries are obtained at a lower level of recovery. Analysis is usually done in duplicate or more, and the coefficient of variation (CV) should be less than 10% to ensure that recoveries will be consistently within the range 70-110%. 

Analytical methods, particularly those used by accredited laboratories, have to be validated according to official rules and regulations to characterize objectively their reliability in any special field of application (Wegscheider [1996] EURACHEM/WELAC [1993]). Validation has to control the performance characteristics of analytical procedures (see Chap. 7) such as accuracy, precision, sensitivity, selectivity, specificity, robustness, ruggedness, and limit values (e.g., limit of detection, limit of quantitation). 

The underlying calibration procedure of a newly developed analytical method has to be examined by basic validation studies to determine the reliability of the method and its efficiency in comparison with traditional methods. In order to ensure long-term stability, it is necessary to perform revalidations, which can be combined with the use of quality control charts, over meaningful time periods. 

According to USP 28 [1], validation of an analytical method is the process by which it is established, through the conduct of laboratory studies, that the performance characteristics of the method meet the requirements for the intended analytical applications. Therefore, validation is an important step in determining the reliability and reproducibility of the method because it is able to confirm that the intended method is suitable to be conducted on a particular system. 

Also, according to these regulations [21 CFR 211.194(a)(2)], users of analytical methods described in the USP and the NF are not required to validate accuracy and reliability of these methods, but merely verify their suitability under actual conditions of use... ... 

In the introductory section to each chapter, there is a brief explanation of the scientific basis of the topic and this is followed by a discussion of the analytical methods which are relevant. While it is not intended that it should be a book of recipes , technical details for many of the methods described are given. This will help those readers with no practical experience to appreciate the steps involved in the analysis while at the same time giving sufficient detail for the method to be developed in practice. It is intended that the book will provide enough information to enable a student to select a technique or series of techniques which would be appropriate for a particular analytical problem and to be able to develop a valid and reliable analytical method. 

A rationale should be generated to explain and support the reasoning for validating the selected parameters. The use of reference standards during validation helps to reinforce the reliability of the analytical method developed. The conditions of how a test is performed may have a strong influence on the results. These conditions have to be recorded and followed. 

Final methods are developed for transfer to operational quality control (QC) laboratories for the release testing of production batches. Additionally, the methods are intended to be applied during Registration Stability studies and for the release of the DP or DS validation batches during the pre-approval development stage. The analytical methods should last for the entire product lifetime therefore, the aim of final method development is to generate fast, robust, reliable, and transferable HPLC methods (preferably isocratic and at low cost). 

Analytical data generated in a testing laboratory are generally used for development, release, stability, or pharmacokinetic studies. Regardless of what the data are required for, the analytical method must be able to provide reliable data. Method validation (Chapter 7) is the demonstration that an analytical procedure is suitable for its intended use. During the validation, data are collected to show that the method meets requirements for accuracy, precision, specificity, detection limit, quantitation limit, linearity, range, and robustness. These characteristics are those recommended by the ICH and will be discussed first. 

Reliable quality control in the field of pharmaceutical analysis is based on the use of valid analytical methods. For this reason, any analytical procedures proposed for a particular active pharmaceutical ingredient and its corresponding dosage forms shonld be validated to demonstrate that they are scientifically sonnd nnder the experimental conditions intended to be used. Since dissolntion data reflect drng prod-net stability and quality, the HPLC method used in snch tests shonld be validated in terms of accuracy, precision, sensitivity, specificity, rngged-ness, and robustness as per ICH guidelines. 

Finally, process analytics methods can be used in commercial manufacturing, either as temporary methods for gaining process information or troubleshooting, or as permanent installations for process monitoring and control. The scope of these applications is often more narrowly defined than those in development scenarios. It will be most relevant for manufacturing operations to maintain process robustness and/or reduce variability. Whereas the scientific scope is typically much more limited in permanent installations in production, the practical implementation aspects are typically much more complex than in an R D environment. The elements of safety, convenience, reliability, validation and maintenance are of equal importance for the success of the application in a permanent installation. Some typical attributes of process analytics applications and how they are applied differently in R D and manufacturing are listed in Table 2.1. 

Validation of analytical methods is important both from the standpoint of good science and to satisfy regulators of the reliability of results reported in dossiers. When approaching validation of any analytical method, one must always ensure that the method is fit for purpose. The amount of resource should be appropriate to the phase of development and the degree to which the process is defined and the methods finalised. 

The analytical methods should be used in the analytical laboratories as the tool to measure the parameters in a way that gives values that are as close to the trae value as possible. The analytical methods should be validated and re-validated to a degree necessary to ensure that the results produced using such methods are sufficiently reliable. Validation data, if properly... 

Several overall conclusions can be drawn based on the statistical evaluation of the data submitted by the participants of the DR CALUX intra-and interlaboratory validation study. First, differences in expertise between the laboratories are apparent based on the results for the calibration curves (both for the curves as provided by the coordinator and for the curves that were prepared by the participants) and on the differences in individual measurement variability. Second, the average results, over all participants, are very close to the true concentration, expressed in DR CALUX 2,3,7,8-TCDD TEQs for the analytical samples. Furthermore, the interlaboratory variation for the different sample types can be regarded as estimates for the method variability. The analytical method variability is estimated to be 10.5% for analytical samples and 22.0% for sediment extracts. Finally, responses appear dependent on the dilution of the final solution to be measured. This is hypothesized to be due to differences in dose-effect curves for different dioxin responsive element-active substances. For 2,3,7,8-TCDD, this effect is not observed. Overall, based on bioassay characteristics presented here and harmonized quality criteria published elsewhere (Behnisch et al., 2001a), the DR CALUX bioassay is regarded as an accurate and reliable tool for intensive monitoring of coastal sediments. 

To provide validation of analytical methods to ensure accuracy and reliability... 

The CISs are rapidly becoming more popular and reliable as their field of application broadens. This is mainly due to the production of surface images by multipoint scanning and mapping. Hyperspectral imaging has proven its potential for qualitative analysis of pharmaceutical products and can be used when spatial information becomes relevant for an analytical application. Even if online applications and regulatory method validation require further development, the power of CIS in quality control and PAT needs no further demonstration, whatever the wavelength domain or method of spectra collection. 

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