Solubility, the phenomenon of dissolution of solute in solvent to give a homogenous system, is one of the important parameters to achieve desired concentration of drug in systemic circulation for desired pharmacological response. Low aqueous solubility is the major problem encountered with formulation development of new chemical entities as well as for the generic development. More than 40% NCEs (new chemical entities) developed in pharmaceutical industry are practically insoluble in water. Solubility is still a major challenge for molecule optimization. Any drug to be absorbed must be present in the form of solution at the site of absorption. The enhancement of the solubility of poorly soluble drugs involves a lot of trials and errors, which calls for AI's guidance. Acknowledgements We thank Prof. Jie Zheng and Zhaoping Xiong, Ph.D. for designing this contest.