Monday, August 30, 2010

Concept of Validation

According to GMP definition Validation is "Establishing documented evidence which provides a high degree of assurance that a specific process will consistently produce a product meeting its pre-determined specifications and quality attributes."

Appropriate and complete documentation is recognized as being crucial to the validation effort. Standard Operating Procedures (SOPs), manufacturing formulae, detailed batch documentation, change control systems, investigational reporting systems, analytical documentation, development reports, validation protocols and reports are integral components of the validation philosophy. The validation documentation provides a source of information for the ongoing operation of the facility and is a resource that is used in subsequent process development or modification activities.

All validation activities will incorporate a level of Impact Assessment to ensure that systems, services and products directly influenced by the testing have been identified.

A revalidation program should be implemented based on routine equipment revalidation requirements and on the Change Control Policy.

Types of Validation

Prospective validation
Establishing documented evidence that a piece of equipment/process or system will do what it purports to do, based upon a pre-planned series of scientific tests as defined in the Validation Plan.

Concurrent validation
Is employed when an existing process can be shown to be in a state of control by applying tests on samples at strategic points throughout a process; and at the end of the process. All data is collected concurrently with the implementation of the process until sufficient information is available to demonstrate process reproducibility.

Retrospective validation
Establishing documented evidence that a process does what it purports to do, based on review and analysis of historical data.

Design Qualification (DQ)
The intent of the DQ is met during the design and commissioning process by a number of mechanisms, which include:

- Generation of User Requirement Specifications
- Verification that design meets relevant user requirement specifications.
- Supplier Assessment /Audits
- Challenge of the design by GMP review audits
- Product Quality Impact Assessment
- Specifying Validation documentation requirements from equipment suppliers
- Agreement with suppliers on the performance objectives
- Factory Acceptance Testing (FAT), Site Acceptance Testing (SAT) & commissioning procedures
- Defining construction and installation documentation to assist with Installation Qualification (IQ).

Installation Qualification (IQ)
IQ provides documented evidence that the equipment or system has been developed, supplied and installed in accordance with design drawings, the supplier's recommendations and In-house requirements. Furthermore, IQ ensures that a record of the principal features of the equipment or system, as installed, is available and that it is supported by sufficient adequate documentation to enable satisfactory operation, maintenance and change control to be implemented.

Operational Qualification (OQ)
OQ provides documented evidence that the equipment operates as intended throughout the specified design, operational or approved acceptance range of the equipment, as applicable. In cases where process steps are tested, a suitable placebo batch will be used to demonstrate equipment functionality.
All new equipment should be fully commissioned prior to commencing OQ to ensure that as a minimum the equipment is safe to operate, all mechanical assembly and pre-qualification checks have been completed, that the equipment is fully functional and that documentation is complete.

Performance Qualification (PQ)
The purpose of PQ is to provide documented evidence that the equipment can consistently achieve and maintain its performance specifications over a prolonged operating period at a defined operating point to produce a product of pre-determined quality. The performance specification will reference process parameters, in-process and product specifications. PQ requires three product batches to meet all acceptance criteria for in-process and product testing. For utility systems, PQ requires the utility medium to meet all specifications over a prolonged sampling period.

The PQ documentation should reference standard manufacturing procedures and batch records and describe the methodology of sampling and testing to be used.

What Gets Validated
All process steps, production equipment, systems and environment, directly used for the manufacture of sterile and non sterile products must be formally validated.

All major packaging equipment and processes should be validated. This validation is less comprehensive.
All ancillary systems that do not directly impact on product quality should be qualified by means of a technical documentation of the extent of the system and how it operates.

- Manufacturing Area Design.
- Personnel and material flow etc.

Process and Equipment Design
Process steps and equipment description. i.e. Dispensing, Formulating, Packaging, Equipment washing
and cleaning. etc

Utility Systems Design
Raw/purified steam, Purified water, Compressed Air, Air conditioning system, Vacuum, Power supply, Lighting, Cooling water, Waste etc

Computerized Systems Design
Information system, Laboratory automated equipments, Manufacturing automated equipments, Electronic records etc

Cleaning Validation (CV)
CV provides documented evidence that a cleaning procedure is effective in reducing to pre-defined maximum allowable limits, all chemical and microbiological contamination from an item of equipment or a manufacturing area following processing. The means of evaluating the effectiveness of cleaning involves sampling cleaned and sanitized surfaces and verifying the level of product residues, cleaning residues and bacterial contamination.

The term CV is to be used to describe the analytical investigation of a cleaning procedure or cycle. The validation protocols should reference background documentation relating to the rationale for "worst case" testing, where this is proposed. It should also explain the development of the acceptance criteria, including chemical and microbial specifications, limits of detection and the selection of sampling methods.

Method Validation (MV)
MV provides documented evidence that internally developed test methods are accurate, robust, effective, reproducible and repeatable. The validation protocols should reference background documentation relating to the rationale for the determination of limits of detection and method sensitivity.

Computer Validation
Computer Validation provides documented evidence to assure systems will consistently function according to their pre-determined specifications and quality attributes, throughout their lifecycle. Important aspects of this validation approach are the formal management of design (through a specification process); system-quality (through systematic review and testing); risk (through identification and assessment of novelty and critical functionality) and lifecycle (through sustained change control).

Where equipment is controlled by embedded computer systems, elements of computer validation may be performed as part of the equipment IQ and OQ protocols.

General process, cleaning and methodology validation concepts are described in this article with a special view to pharmaceutical industry

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