Non-crystalline formulation of lipophilic, surface active and hardly soluble active agents in water-dispersible carrier systems
Special Symposium - Innovations in Food Technology (LMC Congress)
Meals - Convenience, Gastronomy & Quality (Food-1a)
Keywords: o/w-emulsion, water-dispersible, phytosterols, formulation
Many lipophilic active agents like Carotenoids or Phytosterols are insoluble in water and not sufficiently soluble in vegetable oils. Additionally, they can exhibit surface active behaviour leading, in the case of Phytosterols, to undesired interfacial crystallisation.
Nevertheless Phytosterols are of high interest, as they can significantly reduce high serum cholesterol levels and hence the risk for cardiovascular diseases. The dose-response, however, is strongly dependent on their formulation. Crystalline phytosterols exhibit the weakest dose-response. With higher dose-responses of phytosterol fatty acid esters currently applied in commercial functional foods, they still do not reach the level expected from a study for free, dissolved phytosterol molecules.
Up to a concentration of 30 % with regard to the dispersed phase, Phytosterols could be stabilised in a non-crystalline state in sub-micron oil droplets of an o/w-emulsion by means of a high temperature emulsification process combined with a suitable emulsifier system of at least one oil- and one water-soluble emulsifier. Oil droplet diameter was reduced to the range of 100 nm. The emulsion proved to be stable over a period of 60 days as well as during the passage of the stomach until reaching the intestine, which is the site of activity of the Phytosterols.
Liposomes, resembling cell membranes where phytosterols occur naturally, also represent a suitable water-dispersible carrier system for non-crystalline phytosterols and could be loaded with up to 30 % of phytosterols following the film-processing method.
Some surface-active substances are suitable for the production of phytosterol loaded micelles in a watery phase, as well. Until now, only up to 2.5 % phytosterols could be solubilised in mixed micelles. Here, the stability of the micelles turned out to depend on both the Phytosterol- and the dispersed phase concentration.
Presented Wednesday 19, 16:05 to 16:20, in session Meals - Convenience, Gastronomy & Quality (Food-1a).
