by Wolfgang Kempe, IPC Dresden

Many articles in the Glatt International Times have already described the manifold functions of coating, be it for protection against moisture, oxygen, light, be it for taste masking or more sophisticated functions like controlled or target release. The FDA guidelines list a huge number of coating excipients suitable to pass through the gastric tract without creating any damage, amongst them many lipids. Lipids have been used almost 40 years ago to coat food additives, such as vitamins, flavours, preservatives, minerals etc.
Despite the advantages of hot melt coating, such as low cost, optimal hydrophobic films and the benefit of handling a 100% coating liquid, there are also drawbacks:
For achieving good storage stability and uniform spreading of the lipid droplets on the substrate, usually lipids with a high melting point are preferred, which have to be heated far beyond the latter, such presenting the risk of injuries, obstruction of the spray system should there be a temperature drop in the hot melt supply line, higher energy consumption and tedious cleaning procedures.
However, all this has so far been accepted for the high quality of hot melt coating, which compares positively with alternative coating options.
Our product development team at IPC Dresden took the challenge of looking into less troublesome lipid coating options and came up with a new cold lipid coating technique, cutting out the above listed handicaps.
The core technology for this innovative approach is the preparation of an aqueous lipid/fatty acid emulsion which can be sprayed like any other liquid in fluid bed systems, such being suitable for a wide range of applications.
For instance, citric acid crystals can be encapsulated in a completely closed lipid/fatty acid shell, just like small pieces of fruit, snacks, flavours....you name it!

Furthermore, this innovative technique can be combined with the features of the new Glatt Procell fluid bed, which allows for the production of perfectly round and uniform full fat pellets from about 100 to 1000µ, being ideal carriers for active substances, such as pharmaceuticals, all kind of enzymes and fine chemicals. It can be assumed that it will take considerable time until all feasible applications will be exploited.
Relevant tests for both above described processing options can be run at the laboratories of IPC Dresden, which are also competent and well equipped for process scale-up and industrial contract manufacturing.

Should we have aroused your curiosity, check us out on www.ipc-dresden.de or contact us directly.

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		Wolfgang Kempe received his degree as chemical engineer in 1985, worked as group leader in the German pharmaceutical industry until 1996, when he became laboratory manager of IPC Dresden. Contact: wolfgang.kempe@ipc-dresden.de