Preparation and Characterization of High Purity Anhydrous β-Lactose from α-Lactose Monohydrate at Mild Temperature

Abstract

Lactose is a disaccharide of importance in humans dietary, food products, and the pharmaceutical industry. From the existing isomeric forms, -lactose is rarely found in nature. Thus, in this work, a simple methodology to obtain anhydrous -lactose ( L) from -lactose monohydrate ( L⋅H 2 O) is presented. The L⋅H 2 O powder was dispersed into a basic alcoholic solution (72 hours), at controlled conditions of temperature (27, 29, 31, and 32 ∘ C), without stirring. The slurry was dried at room temperature and characterized. Fourier transform infrared spectroscopy showed the formation of L for the samples prepared at 29 and 32 ∘ C. Raman spectroscopy confirmed this result and suggested the occurrence of crystalline L. Rietveld refinement of the X-ray diffraction patterns was employed to identify and quantify the composition of the isomers. The samples prepared at 29 and 31 ∘ C showed the formation of pure L, while those at 27 and 32 ∘ C showed the presence of L⋅H 2 O and a mixture of the two isomers, respectively. The morphology of the powders was studied by scanning electron microscopy, observing the formation of irregular shape L⋅H 2 O particles and axe-like L particles. Clearly, with this methodology, it was possible to obtain pure, crystalline, and anhydrous L at mild temperature.

A Comparative Approach to Screen the Capability of Raman and Infrared (Mid- and Near-) Spectroscopy for Quantification of Low-Active Pharmaceutical Ingredient Content Solid Dosage Forms: The Case of Alprazolam

“…The presented MIR data and bands interpretation for lactose monohydrate are related to the tentative band assignment reported by Norris and Greenstreet, Wiercigroch et al., and López-Pablos et al. 17–19…”

Porous Lactose as a Novel Ingredient Carrier for the Improvement of Quercetin Solubility In Vitro

“…The FTIR fingerprint region (∼1500–500 cm −1 ) can identify lactose. As shown in Figure 4 (A and B), common lactose and porous lactose have a unique peak at 855 cm −1 , which is the unique peak of α -lactose [ 26 ].…”

Carbohydrate-based Trojan microparticles as carriers for pulmonary delivery of lipid nanocapsules using dry powder inhalation

“…The DSC curve (Figure 6b) of lactose starting material (alpha lactose monohydrate) showed an endothermic peak at 147.5 °C, which corresponds to the loss of water of crystallisation followed by a small exothermic peak at 171.7 °C corresponding to crystallisation of amorphous lactose and the melting endotherm with an onset at 212.8 °C corresponding to melting of anhydrous alpha [49]. PXRD diffractogram (Figure 6c) matched that of alpha lactose monohydrate, which well-defined and sharp peaks observed at 12.5, 16.4, 19.5 and 20.5° 2θ [50]. Spray dried lactose was PXRD amorphous (Figure 6c).…”