This chapter is brief review of solubility and related concepts, lipid-water
partition coefficients and their significance in drug bioavailability. After study of this
chapter, students will be able to:
• Analyze and predict the solubility of drugs.
• Identify factors affecting the solubility of drugs.
• Project the polarity, hydrophilicity, hydrophobicity, lipophilicity of drugs and their
influence on solubility.
• Predict the water or lipid solubility of drugs from their structures.
• Comprehend the concept of partition coefficient.
• Apply the concept of lipid water partition coefficient (LWPC) and its significance in
drug bioavailability and action.
Keywords: Hydrophobicity, Hydrophilicity, Lipid-water partition coefficient,
Lipophilicity, Solubility, Water solubilizing potential.