A big problem for contract manufacturers and finished goods makers in general is the development of a contaminating biofilm on the manufacturing equipment. Even after following GMP, a biofilm can persist. I know at least one large manufacturing plant in this area had a significant biofilm problem with this for years.
For cosmetic chemists, a biofilm in your manufacturing facilities means you have to modify your preservative system to not only resist standard microbes that the product will typically be exposed to, but also formulate to ensure that the contaminating species that gets in your batches during the filling process is killed.
These biofilms can be composed of different species at different manufacturing facilities so your formula preservative system that works in one place may not continue to be effective at a different manufacturing plant.
Fortunately, scientists continue to work on this problem. Here is a new technology from IBM which is able to destroy biofilms. It is a polymer hydrogel that can break through the biofilm and deliver an antimicrobial that kills the microbes. This could revolutionize the disinfecting process in cosmetic manufacturing.
Here’s a video which explains the technology a bit more. Very cool technology which could impact cosmetic chemists in the near future.[youtube=http://www.youtube.com/watch?v=jqJt-whgIUE]