- "Thanks to the influx of cash from our Dycloseral acquisition, our R&D pipeline's fully funded for the next two years. These are exciting times, gentlemen, and it's just the beginning."
- —Justin Claybourne[src]
Claybourne Pharmaceuticals was a pharmaceutical company led by Justin Claybourne. It is located in Star City. After Claybourne was killed by the Hood, with his misdeeds presumably revealed, the company shut down.
After AK Desmond Group caused a massive outbreak of weaponized tuberculosis in Lamb Valley, Claybourne Pharmaceuticals immediately increased the price of the Dycloseral drug that they recently acquired rights to, from $10 a pill to $1,000 overnight, making it impossible for the middle-class residents of Lamb Valley to get their hands on the cure. This caused the Hood to suspect Justin Claybourne as the man behind the crisis, which was proven correct. After Claybourne refused to correct his misdeeds, the Hood hunted him down at AK Desmond Group's hideout and killed Claybourne, along with most of his guards. After their CEO's death, the company shut down.
About four years later, Prometheus made a hideout in an old manufacturing plant of Claybourne Pharmaceuticals. He managed to re-activate the production of the Dycloseral drug, with the manufacturing plant reporting heavy usage of water and power over the last few months before December 2016. Team Arrow tracked down and fought Prometheus at this hideout, with Oliver initially suspecting him to be Claybourne himself. After Evelyn Sharp's betrayal and Prometheus's escape, the vigilantes left the plant. It was later investigated by Detective Billy Malone, who located a baby photo at the company's CEO's office, causing Team Arrow to suspect Prometheus to be Claybourne's child. The Throwing Star Killer refused to confirm anything, abducting Billy and using him as bait for Oliver Queen at AK Desmond Group's old hideout.