Process of preparing active pharmaceutical ingredient salts

A process of preparing a salt of an active pharmaceutical ingredient, the process comprising providing a blend of an active pharmaceutical ingredient and a salt forming substance, mixing the blend in an extruder or a granulator with a heated barrel, optionally in the presence of added water, wherein at least a portion of the heated barrel is heated to a temperature of between 100° C. and 200° C., to react the active pharmaceutical ingredient with the salt forming substance to provide the salt of the active pharmaceutical ingredient in a free flowing powder form;

• wherein when the active pharmaceutical ingredient is acidic, the salt forming substance is a base and the pKa difference between the acidic active pharmaceutical ingredient and the base is greater than 1;
• or when the active pharmaceutical ingredient is basic, the salt forming substance is an acid and the pKa difference between the basic active pharmaceutical ingredient and the acid is greater than 1;
• wherein the process comprises directly compressing the salt of the active pharmaceutical ingredient in the free flowing powder form to form an orally disintegrating tablet without a further granulation or micronization step wherein the process is a continuous process;
• and wherein a molar ratio of the salt forming substance to active pharmaceutical ingredient provided in the blend is 1:1 or higher.