Preformulation Studies:contents Physicochemical properties of the drug 。Solubility 。pKa .Partition Coefficient (lipophilic vs.hydrophilic) .Crystal Properties and Polymorphism Particle size,shape and surface area 。Hygroscopicity Stability 。Chemical stability In solid state In solution phase Compatibility Stability in the presence of excipient Biopharmaceutics researchPreformulation Preformulation Studies: contents Studies: contents ™ Physicochemical properties of the drug Physicochemical properties of the drug z Solubility z pKa z Partition Coefficient ( Partition Coefficient (lipophilic lipophilic vs. hydrophilic) vs. hydrophilic) z Crystal Properties and Polymorphism z Particle size, shape and surface area z Hygroscopicity ™ Stability Stability z Chemical stability Chemical stability z In solid state & In solution phase In solid state & In solution phase ™ Compatibility Compatibility z Stability in the presence of excipient ™ Biopharmaceutics Biopharmaceutics research research