Preformulation studies characterize the physical and chemical properties of drug molecules to develop safe, effective, and stable dosage forms. The goals are to develop formulations that are stable, safe, and effective. Major areas of study include physical characterization of properties like crystallinity and polymorphism, hygroscopicity, particle size, and powder flow. Solubility is analyzed through measurements of ionization, partition coefficient, aqueous solubility, and pH-solubility profiles. Stability is analyzed through studies of photolytic stability, stability to oxidation, and drug-excipient compatibility.