allelipraise's version from 2017-06-21 11:26

Section 1

Question Answer
AntioxidantReducing Agents
Antioxidant:Mechanisms of ActionEither the antioxidant is oxidized in place of the active constituent
Antioxidant:Mechanisms of Action If the active component is oxidized, the antioxidant reduces it back to its normal oxidation state

Section 2

Question Answer
Hypophosphorus AcidAcidic properties/Reducing Properties • Readily oxidized to phosphoric acid.
Hypophosphorus AcidDecomposition of acid-When heated between 130o and 140oC, it decomposes into phosphorous acid and hydrogen phosphide (phosphine)
Hypophosphorus Acid:UsesHypophosphorus and its salts (hypophosphites) have no pharmacological actions
Hypophosphorus Acid:UsesAntioxidant (0.5 to 1%): HI Syrup and FeI2 syrup
Hypophosphorus Acid:UsesPreservatives in certain foods

Section 3

Question Answer
Sulfur DioxideStrong reducing agent/As the pH approaches neutral to alkaline values, SO2 is converted almost totally to bisulfite and sulfite.
Sulfur Dioxide:Uses– Preservatives – Because of its gaseous state, it is usually used in injectable preparations enclosed in a single-dose ampules or multiple-dose vials.
Sodium BisulfiteSodium Hydrogen Sulfite, Sodium Acid Sulfite
Sodium Bisulfitemixture of NaHSO3 and Na2S2O5
Sodium Bisulfite– White or yellowish crystals or a granular powder – Unstable to air, giving off SO2
Sodium BisulfiteNeutralized by acids (e.g. HCl) yielding sulfurous acid
Sodium BisulfiteReducing Agent
Sodium BisulfiteIndicator: Starch
Sodium Bisulfite:Commercial Bisulfite (Preparation)Metabisulfite (Na2S2O5) + water
Sodium Bisulfite:Uses – Externally used against parasitic skin diseases – Internally used as antiseptic in gastric fermentation

Section 4

Question Answer
Sodium Metabisulfite(Na2S2O5)Disodium Pyrosulfite
Sodium Metabisulfite:uses – Usually found in solutions of drugs that contain the phenol or catechol nucleus (phenylephrine and epinephrine) to prevent oxidation of these compounds to quinones.
Sodium Thiosulfate(Na2S2O3)Sodium hydrosulfite
Sodium Thiosulfate– Efflorescent at above 23C – Deliquescent at moist air.
Sodium Thiosulfate– Redox reaction (manifestation: decolorization)
Sodium ThiosulfateAntidote for cyanide poisoning
Sodium ThiosulfateAntidote for arsenical and heavy metal poisoning (without sound experimental basis)
Sodium Thiosulfate:UsesInfrequently used as a cathartic and as an antiseptic wash to combat ringworm and other parasitic skin diseases.

Section 5

Question Answer
Sodium NitriteDeliquescent when exposed to atmosphere and subsequently converted to sodium nitrate.
Sodium NitriteReducing Agent /Oxidizing Agent
Sodium NitriteAssay: • Permanganometry
Sodium NitriteRelaxes smooth muscle (esp smaller blood vessels)
Sodium NitriteAntidote for cyanide poisoning
Sodium Nitrite:USESAnti-Rust Tablets – Hypotensive

Section 6

Question Answer
Nitrogen:Inert gasCan be used to protect chemicals, reagents, and pharmaceuticals from air oxidation by displacing the air in reaction vessels and containers.
Nitrogen: USES Retards oxidation of sensitive products (oil, vitamins, etc)