What caused dexamethasone injection prices to surge up to 282-fold in China during 2022-2023?

What caused dexamethasone injection prices to surge up to 282-fold in China during 2022-2023?
The dramatic price spike in dexamethasone sodium phosphate injections was not a simple supply-demand issue but the result of coordinated market manipulation. Three major API producers—Tianjin Pharmaceutical, Zhejiang Xianju Pharma, and Jiangsu Lianhuan—colluded from November 2021 to March 2024 to fix raw material prices, with an individual coordinator named Guo Xiangguo organizing the scheme and even buying up APIs through commercial companies to ensure the cartel held. Hospital purchase prices jumped from RMB 0.35 per vial to as high as RMB 98.76 in some regions, while national hospital sales soared from just over RMB 100 million in 2021 to RMB 916 million by 2023. The Tianjin market regulator imposed combined penalties of RMB 326 million on the companies, plus a RMB 5 million maximum fine on Guo. This case highlights how a small number of domestic API producers can leverage their market position to distort downstream pricing in essential medicines.