Drug discovery and development process aims to make available new pharmacological entities to prevent, treat, mitigate or cure disease in a safe and effective manner. It involves rigorous testing and optimization of selected compounds to identify the drug that is most effective. Drug development starts with a target identification and validation, followed by drug candidate (hits) discovery, and lead drug (compound with favourable pharmaceutical, safety, efficacy and pharmacokinetic profile) selection and optimization then preclinical research, clinical research, FDA drug review, FDA post-market drug safety monitoring. In the stage of preclinical study, pharmaceutical preformulation and development and toxicity studies are the major concerns. The chapter focuses on preclinical formulations stressing upon different preclinical formulation strategies and deciphers the understanding of formulation approaches that could be employed. During preformulation studies the parameters evaluated are: solubility in different media and solvents, dissolution of the active pharmaceutical ingredient (API), accelerated stability studies under various conditions, solid state properties (polymorphs, particle size, particle shape, etc.), formulation development of new chemical entity (NCE),optimization of existing formulations, process development for selected dosage form, novel formulations for improved delivery of existing dosage forms, controlled release and sustained release formulations, micro and nano formulations, partition coefficient, pKa determination. It also emphasizes on Pharmacokinetic studies. The chapter also provides detailed information related to a vast pool of excipients available which is of immense help in designing preclinical formulations. A light is thrown on key aspects of preclinical formulation development by cited examples.