A massive volume of expired medications amasses annually around the world because of pharmaceutical overprescription, combined with overproduction. The accumulation of pharmaceutical waste imposes ecological, economic and social/ethical burdens. Managing this presumed “waste” has developed into a global challenge due to the absence of specific regulations, unreasonable behavior of the patients, and an improper understanding of the concept of “expired medications” in general. This paper summaries, first, the recent literature reporting practices related to the disposal of unused medications. In this context, 48 papers from 34 countries with a total of 33,832 participants point towards a significant lack of public awareness regarding the appropriate disposal of such biologically potent chemicals. These findings are corroborated by a local survey on the disposal practices of unused medicines among pharmacy students at Saarland University. The regulatory aspects surrounding this topic, often based on the official guidelines for the disposal of expired medications and local waste management strategies, are then discussed in light of these findings. Finally, a closer inspection of the epistemic values of expired medications and different strategies for managing expired medications have been reviewed.

Background: Microorganisms commonly employed in food industry, such as Lactobacillus plantarum and Saccharomyces cerevisiae, are also excellent natural nanotechnologists. They reduce selenite (SeO3 2- ) to form nanoparticles of red selenium (Se0 ) of exceptional quality and with interesting physical and (bio-)chemical properties. Objectives: The production of these nanoparticles has been studied in several relevant microorganisms to gain a better picture of the overall properties and quality of these particles, possible differences between producers, ease of production and, in particular, biological activity. Methods: Several common microorganisms, namely L. plantarum, S. cerevisiae and Escherichia coli have been cultured under standard conditions and 1mM concentrations of SeO3 2- have been converted to red particles of elemental selenium. These particles have been characterized extensively with respect to uniformity, size, shape, consistency and, in particular, biological activity against infectious microbes. Results: Highly uniform amorphous spherical particles of 100 nm to 200 nm in diameter could be produced by several microorganisms, including Lactobacillus. Although originating in bacteria and yeast, these particles exhibit antimicrobial activity when employed at concentrations of around 100 µM. This activity may in part be due to the inherent chemistry of selenium and /or of the protein coating of the particles. Interestingly, yeast also forms larger rod-like structures. These micro-needles with around 85 nm in diameter and up to 3 µm in length exhibit considerable antibacterial activity, possibly resulting from additional, physical interactions with cellular structures. Conclusion: Common microorganisms traditionally employed in the preparation of food produce nanoparticles of selenium which may be harvested and explored as natural antimicrobial agents or antioxidants. These particles provide a fine example of and lead for natural nanotechnology with biological activity and applications in food and food supplementation, medicine, agriculture and cosmetics.

Numerous secondary metabolites found in edible plants modulate intracellular redox processes and are suggested to prevent certain diseases, especially in ageing organisms. Since such nutraceuticals provide the basis for new and innovative designer diets and therapies, extracting these substances and their potential from plants has become a focus of research, with nanotechnology and natural nanoparticles at the centre of some of these developments.