In the pharmaceutical world, particle size analysis has traditionally been the method of choice to “characterize” raw materials. Beginning with sieve analyses all the way to more current technologies like laser light scattering, this physical characterization measurement has been used to set incoming raw material specifications, help determine which excipients will be used in a formulation, and troubleshoot product performance issues such as dissolution. While particle size analysis is, without a doubt, an important piece of the puzzle, it is exactly that – a piece. Other measurements can provide essential and useful information as well and, when paired with other techniques, assist the pharmaceutical scientist to more fully characterize their Active Pharmaceutical Ingredients (API) and excipient materials. Among these techniques is the measurement of surface area.