Photodegradation of Oxytocin and Thermal Stability of Photoproducts

ABSTRACT:Photodegradation of oxytocin at λ = 253.7 nm and λ ≥ 290 nm results in the transformation of the intrachain disulfide bond into predominantly dithiohemiacetal and thioether. Especially the dithiohemiacetal is sensitive to further degradation by light and/or elevated temperature, implying that the combination of an initial photostress and a subsequent heat stress can yield products significantly different compared with those observed under heat stress only. © 2012 Wiley Periodicals, Inc. and the American Pharmacists Association