What is Microencapsulation

Microencapsulation technology has been used commercially since the 1950s when it became established as the basis for carbonless copy paper and is now used widely within the food processing, paper, pharmaceutical, agrochemical and cosmetic/personal care industries. Similarly the technology has played a significant role in new developments in the textile industry and has been used for example to impart a range of long-lasting finishes to textile materials including, fragrances, antimicrobials, insecticides, fire retardants and temperature control phase change materials. Micro-encapsulation has also been the major force behind the rise of ‘Cosmeto-textiles’ delivering moisturising agents, vitamins and anti-wrinkle/anti-ageing active ingredients onto the skin.
Microencapsulation is a process by which very tiny droplets or particles of liquid or solid material are surrounded or coated with a continuous film of a polymeric material. The ingredient to be encapsulated is usually referred to as the core material, however, can also be called the internal phase, active, encapsulate, payload or fill. The coating of the microcapsule is generally referred to as the wall material with shell, external phase and in some cases membrane also commonly used. The shape of the capsule is generally governed by the physical nature of the core material for example if the core material is a solid or crystalline material then the resulting capsule may be irregularly shaped. However, if the core material is a liquid, a simple spherical capsule containing a single droplet of active ingredient may be formed.
Microcapsules range in size from 100s of microns, down to single microns although 10-40microns is probably most common. Nanocapsules are also available with sizes around or below 1 micron. Typically the core content will be around 80% by weight although anything up to 95% is possible. Follow the links below to find out more about the major microencapsulation technologies and also other technologies used to store and control release active ingredients: