The Principles of Quality Control

In the Principles of Quality course, students use advanced statistics and mathematics to work with operational data. Process technicians collect, organize, and analyze data during routine operations. The statistical approach works well with statistical process control and control charts. A variety of processes can easily be adapted to fit these quality tools. Examples of these include equipment and quality variables process variables include pressure, temperature, flow, level, and analytical parameters. 

Principles of Quality Course Description Study of the background and application of quality concepts. Topics include team skills, quality tools, statistics, economics, and continuous improvement. The focus of the course is on the application of statistics, statistical process control, math, and quality tools to process systems and operations. 

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A reference method is one which after exhaustive investigation has been shown to have negligible inaccuracy in comparison with its imprecision [International Federation of Clinical Chemistry (IFCC), 1979]. With its comparison of inaccuracy and imprecision this definition clearly refers to the principles of quality control in clinical chemistry. Indeed, statistical models such as Youden plots are used to find out whether the error in a pair of results happens by chance (imprecision of the method) or is systematic (inaccuracy) (Youden, 1967). If the results are close to the true values, inaccuracy is negligible in comparison with imprecision. As demonstrated earlier, each analytical procedure has a certain degree of imprecision consequently, the total absence of systematic error can never be proved. Only as the influence of a systematic error is evident in comparison with the influence of chance or random error can the systematic error be demonstrated. 

Application of the principles of quality control to process operations... 

This part concerns the actual quality control system by which the critical product and process parameters that impact final quality attributes are monitored and corrected in the production process. CQP monitoring systems can be based on the principle of a control circle as explained in Section 7.1.3. The following principles must be followed ... 

Ingamells CO, PiTARD FF (1986) Applied Geochemical Analysis, pp L-84.Wiley, New York. International Federation of Clinical Chemistry (IFCC) (1978) Expert Panel on Nomenclature and Principles of Quality Control in Clinical Chemistry. Clin Chim Acta 83 L89F-202F. International Organization for Standardization (ISO) (1993) Guide to the expression of uncertainty. Geneva. 

The principles of quality assurance are commonly related to product and process control in manufacturing. Today the field of application greatly expanded to include environmental protection and quality control within analytical chemistry itself, i.e., the quality assurance of analytical measurements. In any field, features of quality cannot be reproduced with any absolute degree of precision but only within certain limits of tolerance. These depend on the uncertainties of both the process under control and the test procedure and additionally from the expense of testing and controlling that may be economically justifiable. 

Continuous quality control is based on principles that firstly were used in the system of quality control charts (QCC, Shewhart [1931]). Today, admittedly the monitoring of the characteristics of a process or product in order to detect deviations from the target value is not tied to charts but is mostly done by computer, although it is frequently still called a control chart system. 

The seed stock principle for the preparation and quality control of MCBs and WCBs is an essential part of cell banking procedures, regardless of the intended use for the cells. The size of each bank and the level of quality control used are generally dependent on individual requirements and facilities. However, where a cell line or its products is to be involved in procedures under the jurisdiction of regulatory authorities, the cell banking procedures, characterization and quality control must address specific requirements for procedures and documentation. Finally, the intended use of cells or their product must determine the level of quality assurance required, and the person responsible for exploitation of the cells or product must identify the appropriate quality standard and select an agency accredited to that standard. 

In spite of the fact that this is not intended to be a handbook, some very brief comments on what may be considered organizational aspects of laboratory practice may not be out of place. These may be considered within the wider context of precautions that should be exercised in all analytical laboratories. First of all, attention is drawn to the important principles of quality control, to procedures for numerical analysis of data, and to the important issue of documentation, all of which have been covered succinctly in a review (Keith et al. 1983) and more extensively in books (Keith 1988 1992). It cannot be too strongly emphasized that the analyst is part of a team, and that he or she should play an active part in both the planning and execution of the proposed investigation thereby, many pitfalls — and unnecessary irritation — may be avoided. For example, some conflict may arise over the number of samples required to answer the specific questions that are posed, and resolution of this issue should take priority in planning discussions. In addition, the level of accuracy should be decided at the outset, and care taken that sufficient samples are available for duplicates to be preserved for reanalysis if necessary — and that these are preserved in an acceptable manner. It is worth emphasizing that analytical results may be used in social or political contexts in which numbers may be readily misused. The level of accuracy and interpretation of the data are therefore of cardinal importance in such circumstances. 

Principle. Quality control is concerned with sampling, specifications, and testing as well as with the organization, documentation, and release procedures that ensure that the necessary and relevant tests are carried out, and that materials are not released for use, nor products released for sale or supply, until their quality has been judged satisfactory. Quality control is not confined to laboratory operations, but must be involved in all decisions that may concern the quality of the product The independence of quality control from production is considered fundamental. ... 

Personnel matters, premises, equipment, documentation, production, quality control, distribution of the medicinal products, arrangements for dealing with complaints and recalls, and selfinspection, should be examined at intervals following a pre-arranged programme in order to verify their conformity with the principles of Quality Assurance. 

You are right a normal distribution, for the individual observations, or Student s -distribution, for the averages. When the process is under control, its variability is only due to random errors, and for this reason its responses should follow a normal distribution or a distribution closely related to it. This is the basic principle of quality control — again, another consequence of the central limit theorem. 

Organizations can apply the principles of quality improvement to hazard control efforts in a number of ways. 

The proper education of the pharmacist in the community setting has to include theory and principles of quality control in order to allow the pharmacist to work in a responsible way. In some countries specialised courses for community pharmacists are available or even required. In these courses there should be time for the specific problems of the production of medicines in the setting of a community pharmacy. 

Preparations differ in size and complexity. The scale may range from a tailor-made preparation for one patient to a (semi-)industrial production for thousands of patients. The complexity may range from the reconstitution of an authorised medicine to complex preparations from active substances and excipients. In this chapter we focus mainly on stock preparatiOTis. The principles described are equally applicable to simpler preparations such as extemporaneous preparations and even for reconstitution [4]. However, the extent of quality control and validation should be justified by risk assessment [5, 6 and Chap. 21]. 

The main economic objective of process control is to achieve maximum productivity or efficiency while maintaining a satisfactory level of product quality. Manufacturing facilities in the production of chemicals, paper, metals, power, food, and pharmaceuticals require accurate and precise control systems. Although the methods of production vary from industry to industry, the principles of automatic control are generic in nature and can be universally applied, regardless of the size of the plant. 

Describe the content of a course on the basic principles of quality control. 

A solvent free, fast and environmentally friendly near infrared-based methodology was developed for the determination and quality control of 11 pesticides in commercially available formulations. This methodology was based on the direct measurement of the diffuse reflectance spectra of solid samples inside glass vials and a multivariate calibration model to determine the active principle concentration in agrochemicals. The proposed PLS model was made using 11 known commercial and 22 doped samples (11 under and 11 over dosed) for calibration and 22 different formulations as the validation set. For Buprofezin, Chlorsulfuron, Cyromazine, Daminozide, Diuron and Iprodione determination, the information in the spectral range between 1618 and 2630 nm of the reflectance spectra was employed. On the other hand, for Bensulfuron, Fenoxycarb, Metalaxyl, Procymidone and Tricyclazole determination, the first order derivative spectra in the range between 1618 and 2630 nm was used. In both cases, a linear remove correction was applied. Mean accuracy errors between 0.5 and 3.1% were obtained for the validation set. 

Storage and receiving are activities that can greatly contribute to a safe and economic operation. It is here that quality control can be achieved at minimal cost. Label verification and other quality assurance measures can increase the confidence level that the correct chemicals have arrived, thereby potentially circumventing the use of wrong chemicals. Wrongly shipped chemicals can be returned to the manufacturer with minimal or no cost to the batch operation owner. As with all processes and activities it is of great importance to apply the principles of inherent safety, in particular the minimization and attenuation principles (CCPS G- 41). 

There is the potential to develop a protective vaccine/immunization programme for each and every infectious disease. Whether or not such vaccines are developed and deployed is related to the severity and economic impact of the disease upon the eommunity as well as the effects upon the individual. Principles of immunity and of the produetion and quality control of immunological products are discussed in Chapters 14 and 15, respeetively. 

Medicinal products and bulk pharmaceutical chemicals are produced mainly in batch processes. Controlling these products and chemicals at the end of their manufacturing processes is not in line with the general principle of quality assurance, which is that quality should be built into the product. It is then necessary to ensure that appropriate good manufacturing practices are adhered to throughout the manufacture of both bulk pharmaceutical chemicals (active ingredients as well as excipients) and medicinal products. 

The possibilities afforded by SAM-controlled electrochemical metal deposition were already demonstrated some time ago by Sondag-Huethorst et al. [36] who used patterned SAMs as templates to deposit metal structures with line widths below 100 nm. While this initial work illustrated the potential of SAM-controlled deposition on the nanometer scale further activities towards technological exploitation have been surprisingly moderate and mostly concerned with basic studies on metal deposition on uniform, alkane thiol-based SAMs [37-40] that have been extended in more recent years to aromatic thiols [41-43]. A major reason for the slow development of this area is that electrochemical metal deposition with, in principle, the advantage of better control via the electrochemical potential compared to none-lectrochemical methods such as electroless metal deposition or evaporation, is quite critical in conjunction with SAMs. Relying on their ability to act as barriers for charge transfer and particle diffusion, the minimization of defects in and control of the structural quality of SAMs are key to their performance and set the limits for their nanotechnological applications. 

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