According to Professor Daan Crommelin et al. of the Utrecht Institute for Pharmaceutical Sciences at Utrecht and OctoPlus at Leiden, The Netherlands, biopharmaceuticals deserve special attention as they have a number of characteristics that set them aside from low molecular weight drugs.

Their activity depends on their complicated shape based on secondary, tertiary and (sometimes) quaternary structures. These structures cannot be fully defined with our present set of analytical techniques and approaches for potency testing. They are often the same as (or closely resemble) endogenous proteins. This means that in safety testing and clinical test programmes questions have to be addressed regarding species specific responses, selection of dosing schedules and route of administration, and the possible occurrence of immunogenicity. As the conformational structure of a protein is easily disturbed, formulation and handling of biopharmaceuticals needs special attention in order to optimise the therapeutic effect and minimise adverse reaction, amongst which immune responses.

The issue of biogenerics is gaining more and more interest and different critical elements in the development of biogenerics are touched upon.

They conclude that biopharmaceuticals cannot be characterised fully in terms of their structure like low molecular weight drugs. The performance of biopharmaceuticals relies on strict production protocols and close monitoring of their activity in the clinical situation.