with the area of infection and retains its properties in acting upon the infection. In addition to cement nails, antibiotic cement spacers have been used to treat and prevent osteomyelitis, and for a longer period of time. In producing the antibiotic cement material it is necessary to choose antibiotics that will be effective in this hybrid form, it has been found that antibiotics in powder form that are broad spectrum are of best use. There are recommendations for the amount of antibiotic that is used when mixing in with the cement, but industry wide guidelines have not been established. Challenges Development of antibiotics is difficult, whereas many drug discoveries have been a result of concerted effort and intensive research and development, antibiotics have seemingly been discovered by chance. Since 1987 there have been no discoveries or development of a new class of antibiotics. This is partly due to the finicky nature of antibiotics. As most are produced biosynthetically they require an organism to produce. Historically this has meant that different species are grown and observed for any antimicrobial activity. Not only does this require a culturable species to start off with, but the conditions the species are grown in must be adequate for production of antibiotics as well as having the number of antibiotics produced reach a density threshold so that their function can be observed. Another reason behind the lack of new antibiotic production is the diminishing amount of return on investment for antibiotics and thus the lack resources put into research and development by private pharmaceutical companies. The World Health Organization has recognized the danger of antibiotic resistance bacteria and has created a list of "priority pathogens" that are of the utmost concern. In doing so the hope is to stimulate R&D that can create a new generation of antibiotics. In the United States, the Biomedical Advanced Research and Development Authority (BARDA) aims to support the work of the industry to produce new antibiotics. The buildup of inorganic phosphate can limit the biosynthetic production of certain antibiotics, researchers found that by using an inorganic phosphate trapping agent, the phosphate would be sequestered away and antibiotic production would return to normal levels, thus allowing production to continue. Meropenem is mixed with sodium carbonate post-production before being injected into the body, subsequent analysis of this mixture using Nuclear Magnetic Resonance has shown that a second form of Meropenem is produced.