Critical aspects in the application of the principles of good laboratory practice (GLP).

The principles of good laboratory practice (GLP) are very flexible and an accurate interpretation is required in the application phase. Each test facility has to apply the principles of GLP within its own laboratories, taking into account both the cultural and the organisational aspects. Furthermore, the GLP quality system, as all quality systems, is a dynamic, not a static one. Continuous improvement, depending on the evolving state of the art, is essential. As a consequence, there are many difficulties as well as many different ways in applying the principles of GLP. The cultural aspects play an essential role. The knowledge, experience and fully adherence to the GLP principles, combined with the knowledge of the problems linked to the conduct of various types of non-clinical laboratory studies as well as continuous discussion with representatives of regulatory authorities are mandatory in order to select the correct and adequate methods of application.