PHOTOCHEMISTRY the case of photon-induced chain reactions , quantum yields often are above one , but in many other cases , below 0.01 . Therefore , productivity can vary significantly . Lastly , the light source and reactor must generally be in close proximity to each other . The former often needs to be custom-designed for electrical safety compliance . The cooling system will also have to accommodate light source cooling in addition to the exothermic photoreactor . Elaborate safety interlock using PLC is necessary to manage process hazards .
Recent advances
Given all these complex issues and the risk-adverse nature of the pharmaceutical industry , process chemists and engineers traditionally have shunned away from implementing photochemical processes by re-routing synthesis , even if it means less efficient and less green processes . The last decade has witnessed a burst of photochemistry innovations to create chemical structures and drug candidates very efficiently , which are extremely costly to design around ( Figure 2 ). Concurrently , LED technology has matured commercially to produce near monochromatic photons tunable ranging from UVA to infrared ( Figure 1b ).
Figure 2 - Publication counts on photoredox catalysis
Snapdragon ’ s Iris Lab small-footprint continuous flow photoreactor is designed with kilogram-to-tonne production in mind
The importance of this technology was highlighted with the awarding of the 2014 Nobel Prize in Physics to three physicists who developed the technology . The performance metrics of these LEDs has improved by a factor of about 10 compared with conventional lighting , with high efficiency (> 40 % photon from electricity ), high intensity (> 1 W / cm 2 ), long lifetime (> 10,000 hours ) and lower cost . This technological advance , coupled with tighter clinical development timelines for drugs , has shifted
Note : SciFinder search , 23 January 2020 the cost-benefit balance toward implementing photochemical processes for scale-up instead of rerouting synthesis . However , technological and engineering knowhow has been lagging when it comes to photochemical process scale-up . Very few examples of photochemical processes beyond 1 kg have been achieved and even fewer have been performed to cGMP .
Technology platform
Ever since being founded in Massachusetts in 2015 , Snapdragon Chemistry has recognised the emerging trend and strategically invested in developing scalable LED photoreactor technologies from laboratory to scale-up . The key concept is using continuous flow technology , for which high-intensity photons irradiate on transparent tubular reactor channels constructed with perfluorinated polymers or quartz glass ( UVB and UVC ). The surface-to-volume ratio gives excellent uniform exposure of light with substrate and provides excellent heat transfer . The project is the result of years of hard work involving a team of electrical engineers , mechanical engineers , chemists ,
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