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Example 1: Comparison of the salt form and the free base form HCl salt 2-(2-chlorophenyl)-4-[3-(dimethylamino)phenyl]-5-methyl-lH-pyrazolo[4,3-c] pyridine-3,6(2H,5H)-dione was prepared as an HCl salt as follows: The free base is initially solubilized in ethanol. An appropriate volume of a HCl IN solution (in water) is added to a certain volume of the freebase solution in ethanol so that the free base and its counter ion are in an equimolar ratio. The mixture is stirred at 50°C for a few minutes and then the solvents are removed under vacuum.