Ibuprofen crystals with optimized properties.

The common analgesic drug ibuprofen shows bad dissolution and tableting behavior due to its hydrophobic structure. Additionally its high cohaesivity results in low flowability. Because of the bad compaction behavior ibuprofen has to be granulated usually before tableting. Another problem in manufacturing is the high tendency for sticking to the punches. A crystal form with optimized properties of ibuprofen was prepared and characterized in this study. Crystallization was carried out using the solvent change technique in the presence of different water-soluble additives. These additives were only present during the crystallization process and removed after precipitation by a washing process. A nearly pure ibuprofen powder was received, as GC-analysis showed. Plate-shaped crystals with increased powder dissolution, increased flowability and good tableting behavior were obtained. All crystals were determined as isomorphic by DSC and X-ray analysis. Thus the improvement of the substance characteristics of ibuprofen is reached by changes in the outer appearance of the crystals and in surface modifications. Due to the fact that ibuprofen molecules can form hydrogen bonds, additives that can interact with these hydrogen bonds during the crystallization process can modify the properties of the resulting crystals.