Proteins, polysaccharides, and their complexes used as stabilizers for emulsions: alternatives to synthetic surfactants in the pharmaceutical field?

Emulsions are widely used in pharmaceutics for the encapsulation, solubilization, entrapment, and controlled delivery of active ingredients. In order to answer the increasing demand for clean label excipients, natural polymers can replace the potentially irritative synthetic surfactants used in emulsion formulation. Indeed, biopolymers are currently used in the food industry to stabilize emulsions, and they appear as promising candidates in the pharmaceutical field too.

Stabilization mechanism of oil-in-water emulsions by β-lactoglobulin and gum arabic.

Natural biopolymer stabilized oil-in-water emulsions were formulated using β-lactoglobulin (β-lg), gum arabic (GA), and β-lg:GA solutions as an alternative to synthetic surfactants. Emulsions using these biopolymers and their complexes were formulated varying the biopolymer total concentration, the protein-to-polysaccharide ratio, and the emulsification protocol. This work showed that whereas β-lg enabled the formulation of emulsions at concentration as low as 0.

Morphological study of hydroxyapatite nanocrystal suspension.

Nanometer size hydroxyapatite (HA) crystals are prepared by a wet chemical precipitation method at different synthesis temperatures and with various reactant addition rates. The resulting aqueous suspensions are studied in terms of morphology (transmission electron microscope, specific surface area), phase (X-ray diffraction, electron diffraction and infrared spectroscopy) and rheological properties. This work shows that shape, size and specific surface area of the HA nanoparticles are very sensitive to the reaction temperature and also to the reactant addition rate.