Biological drugs consist of high molecular weight active ingredients obtained from biological substrates or originating from biological material appropriately modified by genetic engineering.
In both cases the material is subject to a purification process, but an in-depth characterization of pharmacologically active molecules cannot always be carried out.
Often, the dosage to be used in patients is determined by the measure of biological activity although, with the use of genetic engineering it is possible to obtain highly purified biological molecules, such as monoclonal antibodies, whose activity and dosage can also be expressed in units of weight.
