What Is Potassium Guaiacol Sulfonate?
Potassium guaiacol sulfonate is a compound with expectorant properties.
It is also called potassium 4-hydroxy-3-methoxy benzene sulfonate (IUPAC nomenclature) and sulfoguaiacol. -8, and 78247-49-1.
The compositional formula is C7H7KO5S, but some commercial products clearly state that it is 1/2 hydrate (C7H7KO5S – 0.5H2O).
Potassium Guaiacol Sulfonate Uses
Potassium guaiacol sulfonate is primarily used as an ingredient in OTC drugs. It promotes airway secretion and decreases the viscosity of sputum, making it easier to expectorate, and it also has a weak antiseptic action.
For this reason, it is often one of the ingredients in common cold remedies and antitussives/expectorants. It is an ingredient that makes it easier to produce so-called “phlegm that gets stuck in the throat.”
Properties of Potassium Guaiacol Sulfonate
Normally, guaiacol sulfonate exists in the form of a white crystalline powder. It is easily soluble in water, but somewhat insoluble in methanol and insoluble in ethanol and ether.
Its aqueous solution is slightly acidic, with a pH of 4.0-5.5 in a 5 w/v% solution. The melting point is 231-232°C. It is a chemically stable compound, but the powder is hygroscopic. It may also be altered by light, so light shielding is required for storage.
How to Select Potassium Guaiacol Sulfonate
Potassium guaiacol sulfonate has positional isomers. Potassium guaiacol sulfonate (potassium 4-hydroxy-3-methoxybenzenesulfonate), the expectorant discussed in this section, has a sulfonic acid group (potassium salt) at position 1, a methoxyl group at position 3, and a phenolic hydroxyl group at position 4, out of the three carbons in the benzene ring.
However, it is not clear from the names “potassium guaiacol sulfonate,” “potassium guaiacolsulfonate,” or “sulfogaiacol” which position isomer (which part of guaiacol is sulfonic acid).
Therefore, it is necessary to check carefully whether what you are purchasing is potassium 4-hydroxy-3-methoxybenzenesulfonate. Potassium 3-hydroxy-4-methoxybenzenesulfonate is also available, although it is not widely distributed.
Other Information on Potassium Guaiacol Sulfonate
1. How Potassium Guaiacol Sulfonate Is Produced
It was created in 1881 by the synthesis of a potassium sulfonate derivative from guaiacol. Since then, the method of production of potassium guaiacol sulfonate has been chemical synthesis. Generally, it is synthesized by sulfonation of guaiacol to obtain potassium guaiacol sulfonate, which is then converted to potassium salts.
Guaiacol was first isolated in 1826 from the guaiac resin (Gum guaicum or guaiac resin) obtained from the yuzu tree (Guaiacum officinale). In ancient times, guaiacol was also used as an expectorant.
2. Applicable Regulations for Potassium Guaiacol Sulfonate
However, as a general precaution for chemical substances, dust-protective masks and protective gloves should be worn and the substance should be handled in an environment with a local exhaust ventilation system. Also, avoid mixing with strong oxidizers.