【正文】 ysical attributes would include internal and external diameters, length and color. Chemical characteristics would include raw material formulation. Mechanical properties would include hardness and tensile strength。D) phase, the desired product should be carefully defined in terms of its characteristics, such as physical, chemical, electrical and 11 performance It is important to translate the product characteristics into specifications as a basis for description and control of the product. Documentation of changes made during development provide traceability which can later be used to pinpoint solutions to future problems. The product39。 deviations which states, in part: There shall be written procedures for production and process control designed to assure that the drug products have the identity, strength, quality, and purity they purport or are represented to possess. 8 Several sections of the CGMP regulations state validation requirements in more specific terms. Excerpts from some of these sections are: Section , Sampling and testing of inprocess materials and drug products. (a) ....control procedures shall be established to monitor the output and VALIDATE the performance of those manufacturing processes that may be responsible for causing variability in the characteristics of inprocess material and the drug product. (emphasis added) Section , Control of Microbiological Contamination. (b) Appropriate written procedures, designed to prevent microbiological contamination of drug products purporting to be sterile, shall be established and followed. Such procedures shall include VALIDATION of any sterilization process. (emphasis added) VI. GMP REGULATION FOR MEDICAL DEVICES Process validation is required by the medical device GMP Regulations, 21 CFR Part\820. Section requires every finished device manufacturer to: ...prepare and implement a quality assurance program that is appropriate to the specific device manufactured... 9 Section (n) defines quality assurance as: ...all activities necessary to verify confidence in the quality of the process used to manufacture a finished device. When applicable to a specific process, process validation is an essential element in establishing confidence that a process will consistently produce a product meeting the designed quality characteristics. A generally stated requirement for process validation is contained in section\: Written manufacturing specifications and processing procedures shall be established, implemented, and controlled to assure that the device conforms to its original design or any approved changes in that design. Validation is an essential element in the establishment and implementation of a process procedure, as well as in determining what process controls are required in order to assure conformance to specifications. Section (a)(1) states: ...control measures shall be established to assure that the design basis for the device, ponents and packaging is correctly translated into approved specifications. 10 Validation is an essential control for assuring that the specifications for the device and manufacturing process are adequate to produce a device that will conform to the approved design characteristics.VII. PRELIMINARY CONSIDERATIONS A manufacturer should evaluate all factors that affect product quality when designing and undertaking a process validation study. These factors may vary considerably among different products and manufacturing technologies and could include, for example, ponent specifications, air and water handling systems, environmental controls, equipment functions, and process control operations. No single approach to process validation will be appropriate and plete in all cases。 ., validation and endproduct testing are not mutually exclusive. The FDA defines process validation as follows: Process validation is establishing documented evidence which provides a high degree of assurance that a specific process will consistently produce a product meeting its predetermined specifications and quality characteristics. 6 It is important that the manufacturer prepare a written validation protocol which specifies the procedures (and tests) to be conducted and the data to be collected. The purpose for which data are collected must be clear, the data must reflect facts and be collected carefully and accurately. The protocol should specify a sufficient number of replicate process runs to demonstrate reproducibility and provide an accurate measure of variability among successive runs. The test conditions for these runs should enpass upper and lower processing limits and circumstances, including those within standard operating procedures, which pose the greatest chance of process or product failure pared to ideal conditions。 (2) quality cannot be inspected or tested into the finished product。s characteristics. Retrospective validation Validation of a process for a product already