Gels that can store and release aromatic oils have been developed by scientists in the US. The gel particles are made from oppositely charged surfactants and polymers and could be used in cosmetic or pharmaceutical products.

The team, led by Eric Kaler at the University of Delaware, Newark, monitored the rate of release of oil from gels into different solvents. They found that the release rate depends upon how easily the oil dissolves and diffuses into the gel matrix. By modelling these factors, the authors say they can design systems with tailor-made release properties. 

Kaler says that by reducing the size of these particles and changing the materials used, they may be able to carry other cargos. 'It will be interesting to form similar particles from biocompatible surfactants and polyelectrolytes which will enable their application in drug delivery,' he said. Kaler is also considering ways to improve the shelf life of these products. 'In this type of encapsulation device, the oil droplets are not indefinitely stable inside the gel matrix.' 

Peter Griffiths of Cardiff University, UK, said the work is significant. 'This offers a new avenue to the formation of insoluble aggregates that can encapsulate and subsequently control the release profile of functional molecules,' said Griffiths. 'This represents a solid basis for developing these potentially very important systems.' 

Rebecca Gillan