Inter-laboratory transfer of HPLC methods: problems and solutions

As high-performance liquid chromatography (HPLC), the premier analytical technique in the pharmaceutical industry, becomes more ubiquitous, methods are more frequently being transferred from one laboratory to another. This review will discuss sources of failures to reproduce HPLC procedures, ranging from sample handling and preparation, through mobile phase, injector, column, detector and data manipulation problems. Also to be considered will be the precautions that should be taken, when initially developing a method, to obviate future problems. These precautions include using stable, well-defined analytical columns, buffered mobile phases, low wavelengths (or a mass-sensitive detector) and internal tests for accuracy; based on the author's experiences. Since the laboratory that originally developed the procedure has the moral obligation and, perhaps, the regulatory responsibility to "guarantee" that the method will perform successfully elsewhere, a series of increasingly comprehensive steps will be given, based on practice, to be followed by the laboratory that could not reproduce the procedure. Also to be discussed are approaches for treating methods that were initially successful but have slowly deteriorated and now fail, and several examples of procedures that were not reproducible in some other laboratories.