Less drug residues in the environment

Degradation of diclofenac: less drug residues in the environment

In recent years, an often extremely dangerous high proportion of drug residues has been detected in the environment during investigations repeatedly. Above all, the widespread painkiller Diclofenac represents a major burden. But researchers were now able to show for the first time how the drug can be degraded in the soil and what hinders the degradation.

Burden on the environment

Scientific research shows time and again how drug residues pollute our environment. Although there are always new procedures in place, the residues can hardly be eliminated, according to experts. Consumers are therefore repeatedly asked, among other things, not to dispose of drug residues in the drain. But human excretions also cause the release of drug components, including those of the widely used painkiller Diclofenac. A research team headed by Prof. Bernhard Hauer from the Institute of Biochemistry and Technical Biochemistry at the University of Stuttgart has now been able to show for the first time how this drug can be degraded in the soil and what hinders its degradation.

In the environment, drug residues are repeatedly detected. A drug whose residues pollute the environment is diclofenac. Researchers were now able to show how the painkiller in the soil can be broken down and what hinders the degradation. (Image: denisismagilov / fotolia.com)

Widely used painkiller

Whether bruises or rheumatism: Diclofenac is prescribed as an anti-inflammatory and analgesic drug in Germany alone more than 14 million times a year, according to a statement of the University of Stuttgart.

It claims that more than 90 tonnes of the active substance will be marketed. But the popular remedy is curse and blessing at the same time, because diclofenac is absorbed by the body only to a certain extent.

About 60 percent of the active ingredient is released into the wastewater through natural precipitation, and despite modern wastewater treatment technology, it has not been possible to remove these residues to date.

In the end, the residues accumulate in nature, where the substance is already found in different habitats and also becomes part of the food chain.

So far only the possibility remained, to pursue the whereabouts of the drug in the environment. Techniques to degrade diclofenac molecules and eliminate them from our habitat did not exist.

Interplay of specific microorganisms

In laboratory experiments, scientists at the University of Stuttgart succeeded for the first time in proving the degradation of diclofenac in soil samples. Decisive for the success of this degradation process is the interaction of certain microorganisms.

The decay of the compound is initiated by a so-called carboxylation, an extraordinary reaction in nature. Only by a highly sensitive analytics succeeded in discovering the metabolic product of the microbes.

Similarly, the research team found out what hinders the degradation of diclofenac: These include in particular carbonates or phosphates, which is particularly problematic, as they are also found in considerable amounts in wastewater.

The results of the scientists were published in the journal "Environmental Technology & Innovation".

The Stuttgart researchers now hope that their findings contribute to liberating the environment from one of the numerous anthropogenic substances.

In further work, they want to try to understand the new reaction biochemically and investigate whether it is also applicable to other drugs. (Ad)