An inadequate powder flow leads to problems in tablet manufacturing. The knowledge of minimum flow properties required for successful tableting on a high speed press is critically important to the efficient development of pharmaceutical tablets. This may be achieved by identifying a powder that exhibits minimally acceptable flow properties on a high speed tablet press. A grade of a common tablet excipient, microcrystalline cellulose (Avicel PH102) lies near the borderline between acceptable and poor flow regions during high speed tableting. It can therefore serve as a reference material for judging adequacy of flow properties of prototype formulations by the way of comparison. A powder exhibiting poorer flow properties than Avicel PH102 likely exhibits flow problems and should be avoided. An implementation of this simple approach in formulation development can minimize potential flow problems during large scale tablet manufacture. (C) 2010 Elsevier B.V. All rights reserved.