The Effect of Power, Pulse Rate and Treatment Time of Sonication on the Nucleation and Growth of α-Lactose Monohydrate (α-LM) Single Crystals from Aqueous Solution

In the present study, different kinds of ultrasound variables such as power (P-75W to 225W), pulse rate (Pr-10s to 60s) and treatment time (T-04 min and T-08 min) are employed on the crystallization of - lactose monohydrate (-LM) from aqueous solution. The applied energy density of sonication in aqueous solution shows a profound effect on the nucleation and growth characteristics of -LM as regards the principal benefits such as reduction of induction period and supersaturation levels required for nucleation, decrease in crystal size with narrow crystal size distribution (CSD) and increase in nucleation rate than uninsonated solution, but have no effect on crystal morphology. Ultrasound promotes only -LM nucleation and no nucleation of either both and -L is observed in all the 36 experiments carried out. The form of grown crystals is confirmed by powder X-ray diffraction (PXRD) and their thermal behaviour is studied by differential scanning calorimetry (DSC) analyses. The purity of the grown crystals is determined using automatic digital polarimeter.