The last few years have witnessed an exponential growth in the biotechnology industry which is reflected in the availability of more than one hundred biotechnology molecules in several therapeutic areas There are critical differences between biotechnological and the more common chemical drugs. A chemical drug is a small molecule produced by chemical synthesis with a very well -defined and stable structure, not or barely sensitive to process changes, which is relatively stable.
Biotechnological drug or a bio-pharmaceutical product is a large complex biomol-ecule with a heterogeneous structure, extremely sensitive to process changes and prepared by the use of living systems, such as organisms, tissue cultures or cells, with the large majority manufactured using recombinant DNA technology. This means that a human gene capable of triggering the production of a specific protein is inserted into a living organism and cultured in the laboratory.
The organism incorporates the gene into its cell structure and produces large quantities of the desired protein. This process of producing proteins in living organ-isms is definitely more complex than that associ-ated with chemical synthesis. This makes quality control and final product standardisation much more difficult to achieve. Small changes in the process or any type of contamination may permanently com-promise the final product.
Moreover, and because it is a relatively recent technology, it is even more difficult to find satisfactory monitoring and evalua-tion methods. Regarding protein synthesis, one of the most important issues is related to glycosylation, since this process can influence solubility, degradation and immunogenicity of recombinant proteins. Changes in degradation can produce novel anti-genic epitopes not found in the parent molecule, with potentially increased immunogenicity 4 and biological activity. Metabolic half -life may also be affected. During manufacturing, another important concern is microbial or viral contamination, as well the incor-poration of impurities such as endotoxins or dena-tured proteins, for example. These can change the immunogenicity of a biopharmaceutical, including “erroneous” activation of T and B cells and induce an immune response.
