Thomas Bruckdorfer

PharManufacturing 2007; 34-41

Abstract: In 2006 the market of modern biopharmaceuticals has reached a volume of over .3 billion in USA and over billion world wide (IMS Health, Inc.). It is projected to grow to an annual value of some billion within the next 5 years. The big advantage of proteins, antibodies, siRNA, and other natural products in their usage as drugs is their high specifity in combination with their low side effects. They normally interact with the dedicated target only, and thus do not have activities at any other place in the body. Modern biopharmaceuticals are ideal drugs, however, their significant drawback is their low stability under physiological conditions. Due to the fact that they are similar to biological components, they are easily attacked by the immune system of the body, i.e. by antibodies and proteolytic degradation enzymes. Many efforts have been made by highly sophisticated formulation techniques, special application methods (depots) and chemical modification to improve their pharmacokinetic properties. One recent approach, which shows much better results than other methods tried in the past, is PEGylation, i.e. attaching PolyEthylene Glycol chains (PEG) to the active component. The simplest possibility of PEGylation is attaching a monofunctional PEG chain to a protein, antibody or small drug molecule. Using bifunctional PEGs a link between two compounds can be formed, in order to build dimers or more complex conjugates. Many highly sophisticated compositions are under development and already published.