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 Article written by: Zoë Ayres Review Published Online: 19/02/2014

Selective detection of hydrazine in the presence of excess electrochemically active pharmaceutical ingredients, using Boron Doped Diamond Metal Nanoparticle Functionalised Electrodes
R. B. Channon, J. C. Newland, A. W. T. Bristow, A. D. Ray, and J. V. Macpherson, Electroanalysis, 2013, 25 (12), 2613–2619.


Diamonds Cleaning Up Drug Production

Recently published work at WEIG demonstrates that Diamond coated with nanoparticles of gold and platimum can be used as an effective sensor for the detection of cancer causing chemicals used in drug production.

Today, the medicines and drugs perscirbed by our doctors are the final product of years of research and development. All the effort that goes into new drug design results in a multistep recipe involving the addition, modification and refinement, of many complex chemical components. Some of the ingredients in these drug recipies need specific conditions or adjustments to help them dissolve, mix, breakdown, combine, or even be removed when no longer needed. Often the unique properties of other additive chemicals and solvents are called upon to promote the desired process, these chemicals do not actually form any part of the drug we consume, but rather provide the conditions necessary for the drug to be assembled. However, there is a risk when using these additive chemicals that small amounts may end up in the final drug product as an impurity. If any of theses impurities are present in high enough quantities there is a possibility of causing serious harm to human health. Before a batch of new or exsisting drug can be distributed it is necessary for pharmaceutical companies to meet and exceed the requirements for safe products imposed by governing agencies, such as the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA). That is why the detection and removal of such impurities from drug products is of paramount importance to the industry and results in a demand for innovative technology to detect harmful impurities in a quick, reliable and sensitive manner.

So, what's new?

The work carried out at WEIG proposed a new method for sensing these potentially harmful impurities. The research details a novel sensor which consists of an electrode made from conductive diamond coated with gold and platinum nanopraticles. The sensor has been sucessfully used to detect pharmaceutical impurities, such as hydrazine (HZ). Hydrazine is a genotoxic impurity (GI) meaning that it is harmful to human heath, having both carcinogenic and mutagenic properties.

Why use diamond as the electrode material ?



What is the importance of this publication ?

The work demonstrates that electrodes made from conductive diamond modified with metal nanoparticles can be used to detect HZ. This has various advantages against current methods used by the pharmaceutical industry, including the fact that the method is simple, inexpensive and fast. It is also important that HZ was detected in the presence of common Active Pharmaceutical Ingredients (APIs), such as comon painkillers like Acetominophen (paracetamol) and antipsychotics such as Promazine, indicating common APIs do not interfere with detection.

Future Work

It is considered that by combining the method with hydrodynamic flow systems the limit of detection can be improved to compete favourably with conventional analytical techniques employed in the pharmaceutical industry.