Pharmaceutical Aids: Boric Acid and Inorganic Acids

Boric Acid

Highly toxic when ingested; not absorbed through skin.

NF XV

Specifies boric acid purity between 99.5%-100.5%.

Acids and Bases

Used to convert drugs to suitable chemical forms.

Buffers

Maintain pH within prescribed limits in formulations.

Antioxidants

Prevent oxidative decomposition of active pharmaceutical components.

Water

Primary solvent in most liquid pharmaceutical preparations.

Glass

Common storage and dispensing container for drugs.

Eyewash Concentration

Boric acid solution used at 2.5%-4.5% concentration.

Dilution Requirement

Concentrated solutions must be diluted with equal water.

Crystallization Risk

Boric acid crystallizes with temperature drop; warm solutions.

Boric Acid Molecular Weight

Molecular weight is 61.83 g/mol.

Boric Acid Synonyms

Also known as boracic acid, hydrogen borate.

Natural Occurrence

Found in seawater, plants, fruits, volcanic steam.

Buffer in Ophthalmic Solutions

Boric acid used in specific ophthalmic preparations.

Native Boric

Native form called sassolite.

Boric Acid Forms

Available as scales, crystals, or powder.

Boroglycerin

Compound from boric acid and glycerin, used as suppository.

Boric Acid Toxicity

Precludes use in internal products due to toxicity.

Solubility of Boric Acid

Soluble in water, alcohol; freely soluble in glycerin.

Hydrochloric Acid

Aqueous solution of hydrogen chloride, 35%-38% by weight.

Hydrochloric Acid Properties

Colorless liquid with pungent odor, specific gravity 1.18.

Non-Fuming Solution

Prepared by diluting hydrochloric acid with water.

Primary Salts

Obtained by replacing one proton from boric acid.

Muriatic Acid

Hydrochloric acid derived from brine, corrosive.

Ionization

High ionization compared to most strong acids.

Alkali Metal Salts

Only soluble salts producing alkaline solutions.

Hydrochloric Acid Composition

35%-38% HCl with impurities like chlorine.

Boiling Point of HCl

Approximately 120℃.

Specific Gravity of HCl

About 1.41, indicating density.

Xanthoproteic Test

Yellow stain on tissue from nitration.

Monoprotic Acid

Strong acid donating one proton per molecule.

Oxidizing Agent

Enhances reactions with weakly basic organic molecules.

Hydrochloride Salts

Water-soluble salts formed from weak bases.

Nitrating Properties

Used extensively in organic chemistry for nitration.

Nitration Reaction

Substitutes nitro group for hydrogen in molecules.

Trinitrotoluene Production

Nitration of toluene yields explosive compound.

Diluted HCl Composition

Contains 9.5g to 10.5g HCl per 100ml.

Gastric Juice

Contains 0.2% HCl aiding digestion.

Uses of HCl

Manufactures sulfuric acid, dyes, and explosives.

Gastric Achlorhydria

Condition of hydrochloric acid deficiency.

Pyroxylin USP XVIII

Uses HCl as nitrating agent.

Dosage of HCl

Administered 1-10 cc, diluted with water.

Glutamic Acid Hydrochloride

Preparation to avoid enamel damage.

Phosphoric Acid NF 26

Contains 85%-88% H₃PO₄ by weight.

Hydrolysis of Salts

Salts with other metals yield insoluble hydroxides.

Corrosive Fuming Liquid

HCl has irritating odor, highly corrosive.

Hydrochloric Acid

Liberates HCl in the stomach during digestion.

Nitric Acid

Colorless, syrupy liquid with specific gravity 1.71.

Non-volatile Acid

Does not evaporate easily, used for stability.

Spirit of Nitre

Another name for Nitric Acid, also Aqua Fortis.

Phosphate Buffer System

Uses HPO₄²⁻ and HPO₄¹⁻ for pH regulation.

Pyroxylin

Prepared using Nitric Acid as a dehydrating agent.

Diluted Phosphoric Acid

Contains 9.5g to 10.5g of H₃PO₄ per 100ml.

Strong Ammonia Solution

Contains 27% to 30% NH₃ by weight.

Gastric Stimulant

Strong Ammonia acts as a tonic for digestion.

Sulfuric Acid

Colorless liquid, oily consistency, 94% to 98% H₂SO₄.

Diprotic Acid

Sulfuric Acid can donate two protons (H⁺).

Oleum

Commercial sulfuric acid with about 10% dissolved SO₃.

Ammonium Hydroxide

Another name for Strong Ammonia Solution.

Dehydrating Agent

Sulfuric Acid removes water from substances.

Catalytic Process

One method for industrial preparation of sulfuric acid.

Lead Chamber Process

Another method for producing sulfuric acid industrially.

Specific Gravity of Ammonia

Strong Ammonia has a specific gravity of 0.90.

Irritating Vapor

Strong Ammonia Solution vapors can cause irritation.

Complex Ion Formation

Ammonia forms soluble complexes with metal cations.

Bronsted Base

Sulfuric Acid acts as a Bronsted base in reactions.

Aromatic Ammonia Spirit

Uses sulfuric acid to stabilize ammonium carbonate.

Ammoniacal Silver Nitrate

Prepared using ammonia and sulfuric acid.

Fuming Sulfuric Acid

Also known as pyrosulfuric acid or Nordhausen Acid.

Contact Process

Produces sulfuric acid with desired strength.

Vanadium Catalyst

Used in the Contact Process for sulfuric acid.

Ammonia Water

Diluted strong ammonia solution, also known as household ammonia.

Circulatory Stimulant

Ammonia vapors used for stimulating circulation.

Lead Chamber Process

Produces sulfuric acid with 76% H2SO4 concentration.

Superphosphate

Fertilizer made from calcium phosphate.

Calcium Hydroxide

Strong base, also known as slaked lime.

Diprotic Acid

Sulfuric acid can donate two protons.

Hygroscopic

Rapidly absorbs moisture and CO2 from air.

Caustic Effect

Strong bases cause tissue corrosion.

Potassium Hydroxide

Strong base, rapidly destroys tissues.

Saponifying Agent

Used to hydrolyze fatty acid esters.

Calcium Carbonate Formation

Occurs when calcium hydroxide absorbs CO2.

Volumetric Solutions

Used for titrating acids in chemistry.

Slaking Process

Manufactures calcium hydroxide from calcium oxide.

Sodium Hydroxide

Also known as caustic soda, strong base.

Calcium Hydroxide Solution

Contains at least 140 mg of Ca(OH)₂ per 100ml.

Alkaline Taste

Characteristic taste of sodium hydroxide solution.

Metal Hydroxides Precipitation

Sodium hydroxide reacts with metal salts.

Fluid Electrolyte

Sodium hydroxide used in medical applications.

Emulsifying Properties

Calcium soaps formed from fatty acids.

Hydroxide Ion Concentration

High in sodium hydroxide for chemical reactions.

Sodium Hydroxide

Less deliquescent, milder, and cheaper than KOH.

Industrial Uses

Sodium Hydroxide is extensively used in industries.

Calcium Hydroxide

Absorbs CO₂, useful in gas traps.

Soda Lime

Mixture of NaOH and Ca(OH)₂ for CO₂ absorption.

Sodium Carbonate

Monohydrated form, colorless crystal or white powder.

Molecular Weight of Sodium Carbonate

124 g/mol.

Potassium Hydroxide

Caustic potash, odorless with strong alkaline taste.

Molecular Weight of Potassium Hydroxide

56.11 g/mol.

Physical Form of KOH

White fused masses, pellets, or flakes.