What is driving bulk antibiotic intermediate pricing for macrolides like spiramycin III?

What is driving bulk antibiotic intermediate pricing for macrolides like spiramycin III?
Bulk antibiotic intermediates have been on a recovery path. Key antibiotic intermediates including 6-APA, 7-ACA and sulfur-containing erythromycin-type products all posted price gains over the past year and have largely returned to historical average levels. That matters for spiramycin III because it shares the broader macrolide fermentation and downstream purification chain, so intermediate tightness tends to pass through to derivative pricing. Unlike vitamins, where restocking cycles drive sharper swings, antibiotic intermediates have moved more gradually back toward normal. The structural story is that China's API sector is shifting from a purely cyclical business toward higher-value manufacturing, with capacity built in recent years starting to contribute profit, which supports firmer pricing discipline across macrolide lines.