Quality control protocol design

The design of a total quality control protocol is based upon two fundamental components validation of the method and continuous... 

While methods validation and accuracy testing considerations presented here have been frequently discussed in the literature, they have been included here to emphasize their importance in the design of a total quality control protocol. The Youden two sample quality control scheme has been adapted for continuous analytical performance surveillance. Methods for graphical display of systematic and random error patterns have been presented with simulated performance data. Daily examination of the T, D, and Q quality control plots may be used to assess analytical performance. Once identified, patterns in the quality control plots can be used to assist in the diagnosis of a problem. Patterns of behavior in the systematic error contribution are more frequent and easy to diagnose. However, pattern complications in both error domains are observed and simultaneous events in both T and D plots can help to isolate the problems. Point-by-point comparisons of T and D plots should be made daily (immediately after the data are generated). Early detection of abnormal behavior reduces the possibility that large numbers of samples will require reanalysis. 

The establishment of performance criteria for a given tumor marker test is not a simple process because accuracy and precision are unique for each type of analyte and its application. Establishing methodological limits for accuracy, precision, sensitivity, and specificity often requires standard reference materials, quality control materials, comparative studies, and actual clinical specimens. Accuracy and precision must be measured over the analyte reportable range for which the device is intended to be used. Sensitivity and specificity must be considered with respect to the intended clinical use of the device. Also, the indications for use should be carefully considered in the design of the study protocol. The indications for class II should be to monitor residual tumor after surgery (or radiation), the recurrence of tumor, or response to therapy. A 510(k) must provide clear evidence that the device is accurate, safe, effective, and substantially equivalent to a device legally marketed in the United States. 

ISO, IUPAC and AOAC INTERNATIONAL have co-operated to produce agreed protocols on the Design, Conduct and Interpretation of Collaborative Studies 14 and on the Proficiency Testing of [Chemical] Analytical Laboratories .11 The Working Group that produced these protocols has prepared a further protocol on the internal quality control of data produced in analytical laboratories. The document was finalised in 1994 and published in 1995 as the Harmonised Guidelines For Internal Quality Control In Analytical Chemistry Laboratories .12 The use of the procedures outlined in the Protocol should aid compliance with the accreditation requirements specified above. 

Internal quality control is undertaken by the inclusion of particular reference materials, called control materials , into the analytical sequence and by duplicate analysis. The control materials should, wherever possible, be representative of the test materials under consideration in respect of matrix composition, the state of physical preparation and the concentration range of the analyte. As the control materials are treated in exactly the same way as the test materials, they are regarded as surrogates that can be used to characterise the performance of the analytical system, both at a specific time and over longer intervals. Internal quality control is a final check of the correct execution of all of the procedures (including calibration) that are prescribed in the analytical protocol and all of the other quality assurance measures that underlie good analytical practice. IQC is therefore necessarily retrospective. It is also required to be as far as possible independent of the analytical protocol, especially the calibration, that it is designed to test. 

The physicochemical and other properties of any newly identified drug must be extensively characterized prior to its entry into clinical trials. As the vast bulk of biopharmaceuticals are proteins, a summary overview of the approach taken to initial characterization of these biomolecules is presented. A prerequisite to such characterization is initial purification of the protein. Purification to homogeneity usually requires a combination of three or more high-resolution chromatographic steps. The purification protocol is designed carefully, as it usually forms the basis of subsequent pilot and process-scale purification systems. The purified product is then subjected to a battery of tests, which aim to characterize it fully. Moreover, once these characteristics have been defined, they form the basis of many of the quality control (QC) identity tests routinely performed on the product during its subsequent commercial manufacture. As these identity tests are discussed in detail in Chapter 3, only an abbreviated overview is presented here, in the form of Figure 2.7. 

No adjuvant is licensed as a medicinal product in its own right, but only as a component of a particular vaccine. Therefore preclinical and toxicology studies need to be designed on a case-by-case basis to evaluate the safety profile of the adjuvant and adjuvant/ vaccine combination [60], Evaluation in preclinical studies is important for identifying the optimum composition and formulation process and also for allowing development of tests for quality control [61]. Data from these studies also helps plan protocols for subsequent clinical trials from which safety and efficacy in humans can be evaluated. 

However, the problem of analytical transferability remains. The optimal, but usually very unrealistic, situation assumes that the analytical methods, including their calibration and quality assurance, are identical in the laboratories. A more pragmatic approach involves standardization of analytical protocols, common calibration, design of a sufficiently efficient external quality control scheme, and the use of mathematical transfer functions if the results still are not directly comparable. 

While protocol design in terms of collection of a quality data set (numbers of animals, use of radiolabel, analytical concerns) does not inherendy differ from other species, the way the fish are acquired, acclimated, housed, exposed and sampled can influence the variability and data quality. In general, more experimental control is required for studies with fish. This may be a confounding concern as inherent difficulties may exist in obtaining healthy, genetically pure, easily sexed and experimentally acceptable animals. 

A written validation protocol should be established that specifies how process validation will be conducted. The protocol should be reviewed and approved the quality control unit and other designated organizational units. 

Development of procedures and protocols for a chemical/ vehicle quality control analysis program. Such programs are designed to insure that reliable procedures are used by the bioassay and chemistry laboratories for the analysis of bulk chemicals and chemicals in the dosage/feed mixtures. 

Before a suite of samples can be analyzed, a set of protocols, similar in design to other U.S. EPA ICP-MS analytical procedures such as Method 200.8, must be followed to ensure the instrument is working at its optimum performance. A summary of these protocols is shown in Table 20.2. The analytical run sequence outlined should be performed on a daily basis in order to meet all quality control requirements. (Note The samples shown in the top portion [sequence 1-19] must be run once per sequence, while the 10 samples [sequence 20-22] and the final continuing calibration verification [CCV] and continuing calibration blank [CCB] samples must be repeated.)... 

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