The aim is to perform GLP-complient validation of formulation analytical methods developed for the determination of achieved concentration in animal dosing formulations or special formulations (extracellular solution used in hERG channel test etc).
Formulation analytical methods are validated in terms of selectivity, linearity, precision, accuracy and stability. The general approach is that the method is validated in a narrow concentration range applying strict acceptance criteria as for linearity, system precision, method precision and accuracy. If the acceptance criteria are acceptable, single point calibration is applied during the measurement of formulations originating from an animal trial. Each sample is diluted to the so-called target concentration, the arithmetic mean of the calibration curve. If the above approach cannot be applied a method is validated for a large calibration range.
The concentration of the stability samples, the temperature and the length of storage for the stability test are defined on the basis of information already available about the test item or achieved during in-house preliminary stability testing.