Solubility is one of the most important properties in drug discovery. Low solubility can lead to poor absorption and bioavailability after oral dosing, insufficient solubility for IV dosing, artificially low activity values or erroneous results in different biochemical and functional assays. Low solubility is often associated with high plasma protein binding, slow tissue distribution, and drug-drug interactions. Increased time and resources are required with expensive formulations to develop a poorly soluble drug candidate. Concept use the shake-flask method for either kinetic or thermodynamic solubility depending on your preference.