Lactose in the pharmaceutical industry: properties and applications

Abstract

Lactose, a disaccharide composed of galactose and glucose, is the primary carbohydrate found in mammalian milk and is biosynthesized by the enzyme lactose synthase. Its physicochemical properties, including mutarotation, are influenced by factors such as temperature, pH, and solvent type, making it a compound of significant interest across various applications. In industry, lactose plays a crucial role in both food and pharmacology. It is extensively utilized as a pharmaceutical excipient, particularly in tablets and inhalation powders, owing to its ability to enhance drug stability, solubility, and flow characteristics. The commercial production of lactose involves whey crystallization, yielding either α-lactose monohydrate or anhydrous β-lactose, each possessing distinct properties suitable for different contexts. Furthermore, the reactivity of lactose's hydroxyl groups facilitates the synthesis of derivatives with therapeutic and prebiotic applications, such as lactulose and β-galactooligosaccharides (GOS), which have demonstrated benefits for intestinal health. While the safety of lactose consumption is well-documented, lactose intolerance, stemming from lactase enzyme deficiency, remains a substantial concern for a segment of the population. The stability of lactose monohydrates is critical for ensuring the integrity of pharmaceutical products; however, its reducing potential may necessitate considering alternative excipients in specific formulations or in cases of galactosemia. The global pharmaceutical lactose market is currently experiencing significant expansion, propelled by the growth of the broader pharmaceutical industry and continuous technological advancements, thereby solidifying lactose's position as an indispensable excipient in innumerous applications.