5691. Magnesium Sulfate

Nomenclature

CAS number: 7487-88-9
Sulfuric acid magnesium salt (1:1).
MgO4S; mol wt 120.37.
Mg 20.19%, O 53.17%, S 26.64%.
MgSO4.

Description and references

Monohydrate occurs in nature as the mineral kieserite. Review: Gmelins, Magnesium (8th ed) 27, 210-211, 223-226 (1939). Review of clinical experience: R. Swain, B. Kaplan-Machlis, South. Med. J. 92, 1040-1047 (1999); of toxicology: J. W. Van Hook, Crit. Care Clin. 7, 215-223 (1991); R. B. Birrer et al., J. Emerg. Med. 22, 185-188 (2002). Clinical trial in prevention of eclamptic convulsions: L. Duley et al., Lancet 359, 1877 (2002).

Derivative

Trihydrate.

Nomenclature

CAS number: 15320-30-6
MgO4S.3H2O; mol wt 174.41.
Mg 13.94%, O 64.21%, S 18.38%, H 3.47%.

Description and references

Prepn: Bennett, US 3297413 (1967 to Dow).

Properties

Odorless crystals.

Derivative

Heptahydrate.

Nomenclature

CAS number: 10034-99-8
Bitter salts; epsom salts; Mg 5-Sulfat (Artesan).
MgO4S.7H2O; mol wt 246.47.
Mg 9.86%, O 71.41%, S 13.01%, H 5.73%.

Description and references

Occurs in nature as the mineral epsomite.

Properties

Efflorescent crystals or powder; bitter, saline, cooling taste. d 1.67. Soly in water (g/100 ml): at 20° = 71; at 40° = 91. Slightly sol in alcohol. Its aq soln is neutral. pH 6-7. On exposure to dry air at ordinary temp it loses ≈1H2O; at 70-80° loses 4H2O; at 100° loses 5H2O; at 120° loses 6H2O, rapidly reabsorbing water when exposed to moist air; loses the last mol of water at ≈250°.

Derivative

Dried magnesium sulfate.

Description and references

Prepd by heating the heptahydrate until ≈25% of its weight is lost. Used in Morison's paste.

Properties

Keep well closed.

Caution

Parenteral use or use in presence of renal insufficiency may lead to magnesium intoxication. See: M. J. Ellenhorn et al., Ellenhorn's Medical Toxicology: Diagnosis and Treatment of Human Poisoning (Williams & Wilkins, Baltimore, 2nd ed., 1997) pp 1013-1014. Potential symptoms of overexposure are pseudocoma, hyporeflexia, muscle weakness, ataxia, confusion, nausea, vomiting, flushing, bradycardia, hypotension, widened QRS, AV block and respiratory arrest (Swain, Kaplan-Machlis).

Use

Weighting cotton and silk; increasing the bleaching action of chlorinated lime; manuf mother-of-pearl and frosted papers; fire-proofing fabrics; dyeing and printing calicos; in fertilizers; explosives, matches; mineral water; tanning leather.

Therapeutic Category

Anticonvulsant; cathartic; magnesium replenisher.

Therapeutic Category (Veterinary)

Anticonvulsant; cathartic; magnesium replenisher.

Keywords

Anticonvulsant; Laxative/Cathartic; Replenishers/Supplements; Magnesium