Solutions: Antioxidants Flashcards
Auto-oxidation
Occur spontaneously under normal conditions of preparation, packaging, and storage
Free radical
A chemical species containing an unshared electron in its outer shell
Anti-oxidants
Substances that prevent or inhibit oxidation
Added to dosage forms prone to oxidation
Chelating agents
Organic compounds that can form complexes with metal ones
Inactivated metal ions that catalyze oxidation
Mechanism of chelating agents
Inhibits oxidation by cheating metal ion catalysts (fe, cu, co, ni, mn)
EDTA, citric acid and tartaric acid
Preferential oxidation
Some anti-oxidants are easily oxidized
Lower oxidation potential than the drugs
Protect by getting preferentially oxidized
Also called oxygen scavengers
Oxygen scavengers
Sulfites
Ascorbic acid
Monkthioglycerol
Sodium formaldehyde sulfoxylate
Chain terminators
Provide H atoms or electrons
Converted to less reactive free radicals
Water-soluble anti-oxidants
Monothioglycerol
Examples of reducing agents
Ascorbic acid
Sodium thiosulfate
Oxygen scavengers
Sodium bisulfate
Sodium metabsulfite
Sodium thiosulfate
Sodium formaldehyde sulfoxylate
Chain terminators
Ascorbyl palmitate
BHA, BHT
Propyl gallate
Alpha tocopherol
