Table : The table below shows the model curves used to fit the pH-solubility data and determine the experimental pKas for the compounds. It should be noted that a0, b0, c0 represent the optimization constants being solved. These are pKa1, pKa2 and pS0. The diagram shown in Figure illustrates the experimental design on the HTE platform. Each organic solution is placed on the Freeslate CM3 deck in 20 mL vials on an 8-well plate, along with dispensing heads for each of the drug substances (labeled "API"). Since a greater volume of aqueous buffer is used across all samples in this design, a larger 125 mL glass container holds the aqueous medium. As previously mentioned, seven different solvent combinations were selected. The Mettler Toledo Quantos was used to dispense powder into 8 mL vials which were assembled onto a 24well plate. After each compound was dispensed into the vials, the organic and the aqueous phases were added respectively.