Our technology takes plant pollens or spores and removes the internal genetic material by a simple chemical or enzyme process. This leaves a porous, inert, elastic shell (skeleton) called an exine (the intine may also be present depending upon application). This shell can be filled with an active ingredient and provides protection for its contents until their later release.
Pollen / spores are natural and totally renewable. The exine shell is nitrogen (protein) free and therefore can not have any allergic effect. Each plant produces pollen with a unique single size (monodispersed) and shape and many pollens are readily available commercially in large quantities. Different pollen sources are preferred for different applications.
The exine shells can withstand acid and alkali treatment as well as temperatures of at least 250oC.
They can have anti-oxidant properties enabling them to help preserve the active ingredients where the latter is contained within the shells. They have also been shown to have taste-masking properties. Because of the relatively large central void within the shell, high loading levels can be achieved. This will vary depending upon the pollen size, but can be 4:1 (active:exine, w:w) for a 40 micron diameter particle.
Processing involves removing the genetic material through the permeable exine. Different procedures are required depending upon the required structure and colour of the micro-capsule in the final product. The filling process may be as simple as mixing the exines with an oil and letting the latter migrate through the pores until it is fully encapsulated. For other active ingredients a filling enhancing ingredient such as ethanol may be needed or physical aids such as a vacuum. In order to obtain a controlled release a further co-encapsulation process can be used (see pharmaceutical.)
In this website the term pollen shell, capsule or skeleton refers to exines both with and without the intine layer.