Using lasers to control polymorphisms

Japanese researchers have used lasers to induce selective crystallisation of metastable indomethacin, paving the way for the synthesis of active pharmaceutical ingredients (APIs) that can change their form.

APIs that can change their form — a trait known as polymorphism — are highly sought after in drug development. Different polymorphic forms of the same drug display different characteristics, for example, the metastable phase of the anti-inflammatory drug indomethacin is more soluble than the stable phase. Better solubility enhances how much of a dose circulates effectively in the body after administration, so retaining indomethacin in its metastable phase is therefore desirable. However, scientists have found this difficult to achieve because the drug naturally wants to revert to its dominant stable phase. 

Reported in Applied Physics Express (APEX), Kenji Ikeda and co-workers at Osaka University, together with scientists across Japan, have developed a new technique using lasers to induce selective crystallisation of the metastable form (or α-form) of indomethacin. Their method creates α-form indomethacin, which remains stable in air at room temperature for up to eight months; previous research achieved α-form stability for less than a day. 

Link to this and other highlights of research published by the Japan Society of Applied Physics JSAP.