Validation, method intended outcomes

Demonstrating that an analytical procedure performs as intended is a GMP concem. 9.35-37,128-132 Jo this end, the employed equipment and the design of the method should be such that the intended goals can be met. The method validation delivers the formal proof that the outcome meets the expectations. 

An interesting and useful classification of steps used to assure quality of analytical data (Bansal 2004) has drawn a clear distinction between quahfication of apparatus used to obtain the data and validation of the methods developed to use the apparatus to obtain the data pertinent to a particular analytical problem. Overlaid on this distinction is another, that between tests that must be completed satisfactorily before acquisition of the desired analytical data can begin (instrument quahfication and method vah-dation) on the one hand, and those that are conducted immediately before or simultaneously with data acquisition (system suitability and quahty control checks) on the other. The original paper (Bansal 2004) represented the outcome of a workshop intended to fiU a need for a more detailed scientific approach to what was termed Analytical Instrument Quahfication (AIQ) , particularly in the context of applications in the pharmaceutical industry. Note in particular that qualification of both hardware and software plays an important role in method validation. 

The extent of validation required will depend on the nature of the intended analytical outcomes. Is the method quantitative (i.e., to allow a measure of quantity of some characteristic of the sample, whether it be active ingredient, impurities, or excipient) or is the method simply a determination of what is present (qualitative) In the forensic environment, both qualitative and quantitative data will most likely be required therefore, it is advisable to ensure that the validation covers both aspects. The extent to which validation is conducted and the parameters that should be included have been the subject of several guidance documents produced by a variety of industrial committees and regulatory or advisory bodies. 

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