title: Radiolysis characterization of cetostearyl alcohol by gas chromatography-mass spectrometry.
abstract: Methods for sample preparation, assay test and impurity test were established. Degrees of cetostearyl alcohol (CSA) radiolyses in pure state, ointment base and in chloramphenicol eye ointment (CAPEO) were determined at doses of 25 and 50 kGy. Radiolyses of CSA occur in all cases. The degrees are directly proportional to the irradiation dose in each case. Forty-two impurities and radiolysis products were identified using gas chromatography-mass spectrometry. The radiolysis products were assigned to be n-alkane, n-aldehyde and 2-methyl-1-alcohol. Accordingly, the degradation pathways of cetosteary alcohol were elucidated. Radiolysis behaviors of CSA in pure state, eye ointment base and CAPEO were studied by assay and impurity analyses. The influence of eye ointment matrixes is modest and chloramphenicol molecule exhibits slight scavenger function for cetostearyl. Both qualitative and quantitative data confirm that the radiolysis products of CSA do not cause safety concerns for human use.
authors.affiliation: Institute of Pharmaceutical Science, Swiss Federal Institute of Technology (ETH), Winterthurerstr. 190, CH-8057, Zurich, Switzerland.
authors.forename: Lan
authors.initials: L
authors.lastname: Hong
authors.forename: Hans
authors.initials: H
authors.lastname: Altorfer
mesh_terms: D005233:Fatty Alcohols / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D011675:Pulse Radiolysis / Q000379:methods
chemical_list: D005233:Fatty Alcohols; C010405:cetostearyl alcohol