Do biological medicinal products pose a risk to the environment?: a current view on ecopharmacovigilance

The occurrence of active pharmaceutical substances in the environment is of growing concern. The vast majority of the compounds in question are of low molecular weight, intended for oral use and designed to tolerate, for example, the digestive enzymes in the upper alimentary tract, the harsh milieus found in the acidic stomach, or the microbe rich intestine. Accordingly, these xenobiotic compounds may, due to their inherent biological activity, constitute a risk to the environment. Biological medicinal products, for example recombinant human insulin or monoclonal antibodies, however, are different. They are primarily made up of oligomers or polymers of amino acids, sugars or nucleotides and are thus readily metabolized. They are therefore generally not considered to pose any risk to the environment. Certain classes of biological medicinal products, however, are associated with specific safety issues. Genetically modified organisms as vectors in vaccines or in gene therapy products have attracted much attention in this regard. Issues include the degree of attenuation of the live recombinant vaccine, replication restrictions of the vaccine vector, alteration of the host and tissue tropism of the vector, the possibility of reversion to virulence, and risk to the ecosystem. In this review we discuss the fate and the potential environmental impact of biological medicinal products following clinical use from an ecopharmacovigilance point of view, and review relevant policy documents and regulatory statements.