The early formulation development studies are important for getting good quality data on dose–response and exposure in animal models, particularly when the therapeutic dose is relatively high. These so-called PK/PD (pharmacokinetics/pharmacodynamics) experiments initiate the transition from the research to development stages. A reasonable, well-tolerated formulation at this stage allowing continuity in the subsequent stages significantly adds confidence to the results obtained. Early formulation ingredients should ideally not affect the animal model itself and should be tolerated with repeated and even chronic administration for toxicology evaluation. At this point in time, it is appropriate to develop a patent strategy with the legal group to ensure that the research efforts are properly protected in a timely manner.