This document discusses preformulation studies that are conducted to characterize the physicochemical properties of new drug substances. It covers topics like organoleptic properties, purity, particle size and shape, solubility, and powder flow properties. The goals of preformulation are established as determining necessary physicochemical parameters, kinetic profiles, physical characteristics, and compatibility with excipients. Various methods for analyzing properties like particle size, surface area, and solubility are also summarized.