Researchers at the CSIR and Cipla in India have published a paper in the Journal of Flow Chemistry titled "Continuous flow process for preparing budesonide", involving the Coflore ACR flow reactor.
The abstract of the paper states:
Budesonide, a glucocorticosteroid, is used as anti-asthmatic drug that became generic in 2019. Existing preparation methods of budesonide require utilization of corrosive acids and involve expensive purification process. Thus, a new cost-effective continuous flow process for the synthesis of budesonide which belongs to the class of 16,17 acetals of pregnane core, is discussed in the present research findings. Flow reactor parameters such as flow rate, temperature, residence time, solution volumes, anti-solvents and reactor frequency are subjected to investigation on the preparation of molar ratio of budesonide epimers. Further, the suitable parameters entail for obtaining the desired molar ratio of epimers. In another aspect, particle size optimization studies are also performed to get the desired budesonide solid product. A continuous flow process for preparation of budesonide is identified from the present research investigation which can be readily transferred to industrial scale up.
The researchers state that major benefits of present flow process methodology are reduction in reaction time from 3 h to 5 min, consistent epimer ratio, desired particle size of the budesonide without micronization and safe handling of caustic HBr.
The open access paper is available for download from the following DOI link: https://doi.org/10.1007/s41981-022-00221-5