Description

ABSTRACT

During a study of the crystallization of the drug ibuprofen from ethanolic solutions, it was necessary to measure crystal size distributions. Ibuprofen is hydrophobic and shows a marked tendency to aggregate in contact with water, a possible suspending liquid.  Further the ibuprofen crystals are plate shaped and are easily broken.  A surfactant can be used to “wet” the ibuprofen crystals and reduce aggregation.  With the liquid cell in the Malvern^® laser light scattering sizer, there is agitation and ultrasound can be used.  This paper describes experimental results to determine the extent of de-aggregation and breakage of crystals by agitation and ultrasound in the sizing.  Ultrasound gives very rapid breakage of the crystals while the agitation gives only minor breakage.

Key words: Ibuprofen, Crystal size distribution, Hydrophobic, Plate shaped.