Range

ICH definition: The rangeof an analytical procedure is the interval between

the upper and lower concentrations (amounts) of analytes in the sample (includ-

ing these concentrations) for which it has been demonstrated that the analytical

procedure has a suitable level of precision, accuracy, and linearity (Figure 3.13).

Typically, linearity and accuracy determination covers a wide concentration range

(e.g., 50% of the ICH reporting limit to 150% of specification). However, the

concentration range for precision will be limited by the availability of sample

of different related substance levels. Therefore, to ensure an appropriate method

validation range with respect to precision, it is critical to use samples of low

and high levels of related substance in precision experiments (e.g., fresh and

stressed samples).