Pfizer's COVID-19 oral drug, Paxlovid, also has a molecular structure that includes fragment P2 (Figure 2). So, caronic anhydride (CAS NO.67911-21-1) is also the starting material for Paxlovid. Paxlovid is a new oral antiviral medication to treat mild-to-moderate COVID-19 disease in people who are at high risk for severe COVID-19. Huateng Pharma provides 99+% high purity caronic anhydride with a production capacity of 20 tons per month. We can also provide CDMO services for COVID-19 drugs with sufficient capacity. Contact us at [email protected] now.