Dexamethasone chemistry

CMA/20 polycarbonate/polyether (PC) probes have been implanted subcutaneously in rats in our laboratory up to 7-10 days. This membrane chemistry has been discontinued. Failure after 7 days is typical and appears to be due to the foreign body reaction as localized anti-inflammatory administration (dexamethasone) increased the lifetime. (2) CMA/20 polyarylethersulfone (PAES) probes have been implanted subcutaneously for up to 7 days in our laboratory. Failure rates have not been determined. (3) CMA/20 polyethersulfone (PES) probes have been implanted subcutaneously for up to 14 days in our laboratory. Failure rates have not been determined. 

Open chain ethers are not cleaved by HF or other fluoride sources. Epoxides, however, are easily opened by HF or KHF to fluorohydrins. The reaction has been widely used in steroid chemistry (equation 44). Dexamethasone is still a practical, important corticoid, which is synthesized on an industrid scale with the help of an epoxide-opening reaction (equation 45). 23 7 6 low temperature needed for rigid steroidal epoxides and the high regio- and stereo-selectivity are remarkable. HF/pyridine is even more convenient for the opening of rigid epoxides. Side reactions often predominate with nonrigid, less reactive epoxides. 2 ... 

Glojnaric, L, V. Erakovic, and M. J. Parnham. 2003. Inhibition of serum amyloid A (SAA) release by dexamethasone, azithromycin and clarithromycin during experimental inflammation in BALB/c mice. Clinical Chemistry 49 (Suppl.) A155. 

---