Entrapping small water-soluble ingredients in aqueous environment
Encapsulation technology allows entrapping active ingredients for further delivery to a target location and then - release. Microcapsules are spherical particles with a diameter of between 50 nm to 2 mm having a peripheral wall (or shell) and containing a core substance. The active ingredients of the microcapsule core may be released upon fracture or dissolution of the peripheral wall material or upon exposure to a particular stimulus, for example, heat, mechanical stress, or change in pH.
Microcapsules generally find use in applications where the increased stability or shelflife of the core substance is important or where the release of the core substance needs to be controlled. Industrial applications include pharmaceutical industry (e.g. in drug delivery systems), personal care products for release of fragrance or active ingredients, or in the food industry for the release of flavour and nutrients.
However, the encapsulation of hydrophilic ingredients with low molar mass for further use in aqueous environment remains a challenge. For example, in cleaning products and detergents, it would be advantageous to prevent the premature release of the active ingredient from their microcapsules during storage, but to release it due to fracture during the laundry cycle (bleach) or post-wash on clothes (fragrance).
Academics at the University of Birmingham have developed, for the first time, a novel encapsulation technology which allows entrapment of hydrophilic active ingredients with absolutely no release in aqueous environment. These unique barrier properties are achieved by creating a sandwiched shell structure combining both hydrophobic and hydrophilic material. The demonstration of successful encapsulation confirmed that a salt solution (KCl) did not leach out of the microcapsule at least within 1 month.
- Highly efficient barrier properties: No release of small water-soluble ingredients in aqueous environment;
- Tunable specific ingredient: The materials used to fabricate the microcapsules can be selected to prevent release of a specific active ingredient;
- Tunable release profile: The thickness of the walls can be designed and selected according to the molar mass of the active ingredient to be able to control its release profile;
- Tunable release stimulus: The microcapsules can be designed to enable release of the encapsulated active ingredient at a specific time and/or in the presence of a specific stimulus (pH or mechanical force).
- Drug delivery
- Personal care
- Food and beverages
- Animal and plant nutrition
- Sealants and adhesives