Particle technology applied to a lactose/NaCMC blend: Production and characterization of a novel and stable spray-dried ingredient

Abstract

Lactose is a simple sugar found in milk and is widely used as an ingredient in food, nutraceutical and pharmaceutical industries. Manufacturers prefer to use it in its spray-dried form because it is technologically better than raw material, but it is physically unstable to environmental exposition. This work focuses on the development of a new spray-dried ingredient in the amorphous state using a mix of lactose and sodium carboxymethyl cellulose in different weight ratios that have a higher stability than Spray Dried Lactose. The particles' amorphous state was evaluated via thermal analysis (DSC) and microscopy studies (SEM), and the effect of amorphisation on the particle size, morphology and solubility were studied. The flowability of the spray-dried powders was determined via density measurements and expressed as the compressibility index and Hausner ratio. The innovative ingredient, which was based on a 1:1 NaCMC:lactose blend ratio, was produced with a high process yield (82.2%); the powder resulted in a shapeless microparticulate form with a good flow character, which is also able to control the water uptake during the storage period. The low values of moisture content (<2%) and hygroscopicity (12.9 g/100 g after three months storage) do not affect the powder in the solid state, avoiding plasticization and glassy-rubbery state transition and ensuring long-lasting stability under harsh storage conditions.