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

• Published in: International journal of polymer science Vol. 2018; no. 2018; pp. 1 - 10
• Main Authors: Saavedra-Leos, María Z., Pérez-García, Sergio A., Longoria-Rodríguez, Francisco E., Silva-Cazares, Macrina Beatriz, Leyva-Porras, C., López-Pablos, Ana L., Vértiz-Hernández, Antonio
• Format: Journal Article
• Language: English
• Published: Cairo, Egypt Hindawi Publishing Corporation 01.01.2018; Hindawi; Hindawi Limited
• Subjects: Caustic soda; Chromatography; Conversion; Crystal structure; Crystallinity; Diffraction patterns; Food; Fourier transforms; Isomers; Lactose; Methods; Pharmaceutical industry; Pharmaceutical sciences; Potassium; Prescription drugs; Scanning electron microscopy; Slurries; Sodium; Solvents; X-ray diffraction
• ISSN: 1687-9422; 1687-9430
• DOI: 10.1155/2018/5069063

Lactose is a disaccharide of importance in humans dietary, food products, and the pharmaceutical industry. From the existing isomeric forms, β-lactose is rarely found in nature. Thus, in this work, a simple methodology to obtain anhydrous β-lactose (βL) from α-lactose monohydrate (αL·H2O) is presented. The αL·H2O 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 βL for the samples prepared at 29 and 32°C. Raman spectroscopy confirmed this result and suggested the occurrence of crystalline βL. 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 βL, while those at 27 and 32°C showed the presence of αL·H2O 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 αL·H2O particles and axe-like βL particles. Clearly, with this methodology, it was possible to obtain pure, crystalline, and anhydrous βL at mild temperature.