Compression Ability Improvement By Solvation Desolvation Process - Application To Paracetamol for Direct Compression

Pure paracetamol for direct compression was prepared by recrystallization in dioxane followed by an appropriate drying process. The polyhedric crystals obtained exhibit a sintered like structure. This porous texture induces plasticity and greatly improves the compressibility. The residual solvent content is clearly less than 100 ppm when the drying is progressive. We have attempted to explain the formation of the sintered texture with the intention of applying this process to other drugs or excipients in order to improve their compression ability. In contrast to the usual hydration/dehydration process applied to lactose, the advantage of this process is the finding of a stable desolvated form; the desolvation of a solvate with organic solvent results in stable material whereas the anhydrates are often unstable.