Pharma Aid necessities part 1 Official organic acids

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Acids and Bases Concepts

Question Answer
Arrhenius Concept( Acids)Any substance which is capable of providing hydrogen ions (or protons H+) in aqueous solution.
Arrhenius Concept( basic)Any substance containing hydroxy groups and/or capable of providing hydroxide ion (OH-) in aqueous solution.
BrÖnsted-Lowry Concept: AcidsAny substance capable of donating a proton (H+)
BrÖnsted-Lowry Concept:BasesAny substance capable of accepting a proton (H+) in a chemical reaction
Lewis Acid-Base Concept:AcidsAny substance which can accept a share in a pair of electrons in a reaction. – Electron acceptor (electron seeking, electrophilic)
Lewis Acid-Base Concept:BasesAny substance that donates a pair of electrons to share with an acid in a reaction. – Electron donor (nucleophilic species)
Pearson’s HSAB principleFurther categorizes the acids and bases according to the properties of charge, size
Hard AcidsElectron pair acceptors, having high positive charges, relatively small sizes and unfilled valence shell orbitals, high electronegativity and low polarizabilities.
Hard BasesHigh electronegativity, easily reduced, have stable valence shell structures, low polarizabilities.
Soft AcidsLow positive charges, relatively large sizes, and filled valence shell orbitals, low electronegativity and high polarizabilities.
Soft BasesLow electronegativity, easily oxidized, have empty low-lying orbitals and high polarizabilities.
Dissociation Constant (Ka)A strong acid is an acid that loses its proton easily, while a weak acid holds its proton tenaciously.
pHLogarithm of the reciprocal of the hydrogen ion activity (also as the negative logarithm of the hydrogen ion activity):
Bufferspairs of related chemical compounds capable of resisting large changes in the pH of a solution caused by the addition of small amounts of acid or base.
Buffer ActionAbility to resist pH changes
Buffer CapacityEfficiency to resist pH changes
BloodBlood stays at pH = 7.4, even when various reactions in the body produce much H+ and OH-
Henderson-Hasselbalch EquationUseful in calculating: – pH of a buffer system if its composition is known – The molar ratio of the components of a buffer

Section 2

Question Answer
Boric AcidSal Sedativum Hombergi
– Pearly scales (smooth); Crystalline – suitable for preparing aqueous solution – bulky powder (unctuous) - dusting powders and ointment – Soluble in water & alcohol, freely soluble in glycerin, boiling water and boiling alcohol.Physical properties(Boric Acid)
Can be esterified with other polyhydroxy compounds such as glycol, mannitol and catechol.Chemical properties(Boric Acid)
– Official assay: • 1 N sodium hydroxide • Glycerin (?) • Indicator: Phenolphthalein Official assay:(Boric Acid)
PhenolphthaleinIndicator:(Boric Acid)
intense blue color Borate solution, acidified with HCl, added with iodine TS and polyvinyl alcohol solution(gives what color)?
green- bordered flame H2SO4 and methanol gives what color when ignited?
Boric acid & sodium borate and sodium perborate.Antiseptic properties (BO3)
Primarily (Buffer);ehicle for ophthalmic solutions (1.9% boric acid);Dusting powderUses of Boric acid?
Boric acid ointment (antiseptic) weakly germicide(BO3)
Boroglycerin Glycerite suppository base

Section 3

Question Answer
Hydrochloric AcidColorless, fuming liquid, pungent odor
Strong monoprotic acid;Reacts with metal oxide and hydroxides producing metal chloride and water;Chloride ion causes precipitation of insoluble chlorides of metals such as Ag, Pb, and Hg (I).Chemical properties(HCl)
Pharmaceutical aid (acidifying agent);Forms water-soluble hydrochloride salt when reacted with basic organic compounds.Uses (HCl)
Nitric AcidEau forte (strong water)
– Highly corrosive fuming liquid – Highly irritating odorPhysical Properties
Xanthoproteic test (nitration of aromatic amino acids) – yellow stainChemical Properties
a brown color is produced at the junction of the two liquids.With H2SO4 and ferrous sulfate, (Nitrate)
brownish-red fumes are evolved.When heated with H2SO4, + metallic copper,
do not decolorizeNitrates acidified KMNO4 TS
– No specific action in the body – Used in relatively large doses as potassium and ammonium salts for diuretic effect. Pharmacology (Nitrate)
– Acidifying agent, OA, and nitrating agentUses (Nitrate)
Used in the manufacture of sulfuric acid, coal tar dyes and explosives.Nitric Acid
destroys chancres and warts, but rarely prescribed for internal use.External use of Nitric Acid
Ingestion (damages tissues) and Inhalation (suffocation) can lead to pulmonary edema (congested lungs)Toxicity (Nitric Acid)

Section 4

Question Answer
Phosphoric AcidOrthophosphoric Acid
– Apatite (3Ca3[PO4]2.CaF2 – Phosphorite or Phosphate Rock (Ca3[PO4]2)Occurrence:Phosphoric Acid
– Very deliquescent (crystals) – Colorless and odorless syrupy liquidPhysical Properties:Phosphoric Acid
Strong triprotic acid;Can also act as a basChemical Properties:Phosphoric Acid
pyrophosphoric acidWhen heated to 200C;Chemical Properties:Phosphoric Acid
metaphosphoricWhen further heated to 300C:Chemical Properties:Phosphoric Acid
yield a yellow precipitate that is soluble in 2 N HNO3 and in 6 N NH4OH.Phosphoric Acid With AgNO3
acidified solutions: yield yellow precipitate that is soluble in 6 N NH4OH.Phosphoric Acid With ammonium molybdate TS,
– Buffer systems for maintaining acid-base balance – Metabolism of carbohydrates – Bone formation (calcium phosphate) – Regulation of calcium metabolism and level in the blood.pharmacology:Phosphoric Acid
– Acidifying agent – Buffer – Aids proteolytic enzymes in the formation of peptones (water-soluble protein derivatives) – Dil. H3PO4: antidote for lead toxicity (soluble lead phosphates – deleading the body)Phosphoric Acid Uses

Section 5

Question Answer
Oil of Vitriol (by Basil Valentine)Sulfuric AcidOil of Vitriol (by Basil Valentine)
– Colorless, odorless, hygroscopic liquid of oily consistency – Non-volatile acid – Dissolves in water and alcohol with the evolution of large amount of heat (highly exothermic)Physical Properties:(Sulfate)
– Strong diprotic acid;Dehydrating agent (equation? significance?) – Acid properties – OA • Metals above H: form sulfate salts + H2 gas • Metals below H: Evolution of SO2 – Sulfonating or sulfating agent & others. • Sulfonic acids (equation?)Chemical Properties(Sulfate)
Sulfation An esterification reaction taking place between sulfuric acid and alcohols.
yield a white precipitate that is insoluble in HCl and HNO3.Sulfuric Acid With BaCl2
yield white precipitate that is soluble in CH3COONH4 TS.Sulfuric Acid With Pb(CH3COO)2 TS:
no precipitate (distinction from thiosulfates).Sulfuric Acid w/ HCl:
– Not absorbed in the GIT when administered orally. • Saline cathartics – Injection of sulfates causes diuresisPharmacology (Sulfate)
– Salts of basic organic drug molecules– Dehydrating agentUses(Sulfate)
(Pyroxylin, USP)– Dehydrating agent(Sulfate)