ABSTRACT
The formulation requires mainly three studies for drug development: in vivo efficacy studies, pharmacokinetics (PK) studies, and toxicology studies. The formulation development strategies will not only depend on physicochemical properties, but also on duration of action and the desired route of administration. For a typical oral administration, formulation strategies are similar to that for in vivo PK screening. A common practice in solubilizing water-insoluble compounds is to use water-miscible solvents. Complexation using cyclodextrins (CDs) is another approach that can be used for solubilization. There are mainly three reasons that surfactants are used in formulation: to increase wetting of drugs, which in turn increase the dissolution; to prevent drug precipitation from formulation; and to increase solubilization through micellization. As dilution can be readily attainable on injection or in the stomach and intestinal contents, it reduces the percentage of the drug complex, releasing the free drug that can permeate through biological membranes.
