The analysis of particle size distribution is an important parameter for FDA process validation. The narrower the particle size distribution range, the more product there is being produced that meets the exact particle size specifications for formulation and bioavailability. Both Conical Milling and Hammer Milling are successfully used to regulate particle size and shape, and achieve consistent tight particle size distributions, leading to quality products and efficient production systems. The choice of whether to use Conical Milling or Hammer Milling will be decided by several factors including an evaluation of the type of product that is needed to be processed, and the results required.