Oxidation is a well-known chemical degradation pathway for pharmaceuticals. Oxygen, which participates in most oxidation reactions, is abundant in the environment to which pharmaceuticals are exposed, during either processing or long-term storage. Oxidation of ascorbic acid (Scheme 44) was reported as early as 1940,175176 and many factors affecting ascorbic acid oxidation have been discussed, including the role of metal ions. 177-179
Oxidation mechanisms for drug substances depend on the chemical structure of the drug and the presence of reactive oxygen species or other oxidants. Catechols such as methyl-dopa180 and epinephrine181 are readily oxidized to quinones, as shown in Scheme 45. 5-Aminosalicylic acid undergoes oxidation and forms quinoneimine,182 which is further degraded to polymeric compounds (Scheme 46).183 Ethanolamines such as procaterol are oxidized to formyl compounds (Scheme 47),184 whereas thiols such as 6-mercaptopurine,185
choh choh ch2oh ch2oh choh choh ch2oh ch2oh
Scheme 44. Oxidation of ascorbic acid.
Was this article helpful?
If you're wanting to learn about drug addiction... Then this may be the most important letter you'll ever read You Are Going To Get A In Depth Look At One Of The Most Noteworthy Guides On Drug Addiction There Is Available On The Market Today. It Doesn't Matter If You Are Just For The First Time Looking For Answers On Drug Addiction, This Guide Will Get You On The Right Track.