ABSTRACT
The manufacturing process of botulinum toxin products approved in aesthetic indication starts with the fermentation of Clostridium botulinum type A. The so called Hall strain of Clostridia botulinum type A is employed by the manufacturers, although Allergan's strain Hall-hyper, which might have different sporulation properties, seems to be different. After growth and lysis of the clostridia, the neurotoxin is purified by applying different purification protocols: onabotulinumtoxin is purified by precipitation with ethanol, followed by a series of ammonium sulphate precipitation, and dissolution (“crystallization”) resulting in a large complex composed of the 150kDa neurotoxin attached to several other proteins, the so-called complexing proteins or neurotoxin associated proteins. Toxin with less spreading tendency may work similarly in small muscles to one that is easily spreadable but might appear less effective in a broader muscle because of the reduced coverage when the points of injection are limited.
