Cyclodextrin-panobinostat adduct

A method for producing a cyclodextrin-panobinostat adduct having a concentration of less than 1000 parts per million (ppm) of acetone, tetrahydrofuran, dichloromethane, acetonitrile, dimethylformamide and dimethyl sulphoxide (DMSO),comprising:

• a) providing a first aqueous solution comprising a buffering agent, the solution having a pH in the range 2.0 to 4.0;
• b) dissolving panobinostat in said first aqueous solution to provide a second aqueous solution;
• c) mixing said second aqueous solution comprising panobinostat with a third aqueous solution comprising a cyclodextrin to form a fourth aqueous solution comprising a cyclodextrin-panobinostat adduct;
• and
• d) adding a sufficient quantity of a base to said fourth aqueous solution comprising the cyclodextrin-panobinostat adduct in order to provide a fifth aqueous solution having a pH in the range 6.0 to 8.0.