ANTIOXIDANTS

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PHARMACEUTICAL CHEMISTRY- I
ANTIOXIDANTS
Presented by. Mr. Maroti M. Jeurkar Lecturer,
YBCP, chandrapur
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ANTIOXIDANTS Antioxidants are the agents which
inhibit oxidation and are commonly used to
prevent rancidity of oil and fats or
deterioration of other material through oxidative
process. OR Antioxidants are the agents which
prevent oxidation and deterioration when added to
pharmaceutical preparations.
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• Classification of Antioxidants
• Organic Type
• Hypo-phosphorous acid
• Sodium thiosulphate
• Sodium Metabisuphate
• 2. Inorganic type
• Quiol Derivatives Tocophenol
• Pyrogallon derivatives - Amylgallate
• Amines -
  Lecithines
• Benzoic acid derivatives -Benzoic acid
• Selection of Antioxidants
• 1.Activity
• 2.Redox reaction( oxidation reduction reaction)

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• Properties of Antioxidants
• They should be non-toxic.
• They should be physiologically chemically
  inert(other than the action required to prevent
  oxidation of active ingredient).
• They should be physiologically chemically
  compatible.
• They should not have solubility problem
• They should be effective in very small
  concentration.

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COMPOUNDS
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HYPOPHOSPHORUS ACID Formula H3PO2 Mol. Wt.
- 66.00 Properties - Since Hypophosphorus acid
is readily oxidized by usual oxidizing agents.
It is clear or yellowish liquid, slightly odour,
strong acidic taste Storage - in well
closed container in dark place Uses -
Antioxidants (conc.0.5-1.0) -
Preparation of hydroiodic and ferrous iodide
syrup - etc.
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SODIUM THIOSULPHATE (Antichor, Sod.
Hyposulphate) Formula -Na2S2O3.5H2O
Mol. Wt. -248.18 Properties - Colorless,
Odorless,bitter in taste, crystalline Prism,
effloresence in dry air, soluble in water and
insoluble in alcohol. Use- -
Antioxidants - Antifungal - Fixing
agent in photographic films - Antidote in
cynoid poisoning
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SODIUM METABISULPHATE (Disodium pyrosulphide,
Sod.Pyrosulphide) Formula - Na2S2O5 Mol wt -
190.10 Properties- Colorless White or creamy
white crystalline powder, sulphorous acid Odor,
saline in taste, soluble in water and slightly
soluble in alcohol. Uses- -Antioxidants
-Reducing agent -stabilizer -Fixing agent
in photographic films -Antidote in cynoid
poisoning
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NITROGEN (Disodium pyrosulphide,
Sod.Pyrosulphide) Formula N2 Mol wt -
28.01 Properties - Colorless, Odorless, gas,
soluble in water and alcohol, nitrogen neither
burn nor support in burning combustion. Uses-
-Antioxidants -to preserve packaged foods by
stopping the oxidation of food -to produce
many electrical parts -In health care for
respiratory assistance -it is used as a
carrier gas or mobile phase -i.e
used in gas chromatography
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