Ultrasound-assisted modulation of concomitant polymorphism of curcumin during liquid antisolvent precipitation

• Curcumin polymorphs precipitated concomitantly during liquid antisolvent process.
• Ultrasound was found to affect the percentage of polymorphs in the mixture.
• Lower ultrasonic energy favored monoclinic form in presence of additives.
• Higher ultrasonic energy favored orthorhombic form in presence of additives.
• Orthorhombic forms were found to transform to monoclinic form upon heating.

Curcumin polymorphs were found to precipitate concomitantly during liquid antisolvent precipitation. While, commercially available curcumin exists in a monoclinic form, the curcumin particles when precipitated in presence of additives and ultrasound were either found to be the mixtures of orthorhombic (Form 3) and monoclinic form (Form 1) or were found to be in orthorhombic form (Form 3) or monoclinic form (Form 1). The experimentally observed particle morphologies did not match clearly with the predicted BFDH morphologies of curcumin and the experimentally observed morphologies were more elongated as compared to the predicted BFDH morphologies. At lower ultrasonic irradiation times, the monoclinic form (Form 1) was found to dominate the mixture of particles. However, an increase in ultrasonic irradiation time was found to increase the percentage of orthorhombic form (Form 3) in the particles indicating that the increase in ultrasonic energy facilitates formation of orthorhombic form over the monoclinic form, irrespective of the additive used. These results therefore suggest that the ultrasonic energy can be effectively used to manipulate the polymorphic outcome of the precipitation.

Concomitant polymorphs can be observed, when curcumin was precipitated with ultrasound and sodium alginate, Pluronic F 68, Tween 80 below CMC as additives.Figure optionsDownload as PowerPoint slide