Monosodium Glutamate

Category

Flavoring agent

Molecular Formula

C5H8NO4Na; C5H8NO4Na·H2O

Molecular Weight

169.13(anhydrous); 187.13 (monohydrate)

Grade

Pharmceutical Excipients

Description

Monosodium glutamate occurs as white free-flowing crystals or a crystalline powder. It is practically odorless and has a meat-like taste.

UNII

W81N5U6R6U

Chemical Name

Glutamic acid monosodium salt monohydrate

CAS Number

142-47-2

Synonyms

Chinese seasoning; glutamic acid monosodium salt; glutamic acid, sodium salt; monosodium L-glutamate monohydrate; natrii glutamas; sodium L-glutamate; sodium glutamate monohydrate; sodium hydrogen L-(þ)-2-aminoglutarate monohydrate.

Administration route

Oral

Dosage Form

Oral syrup

Stability and Storage Conditions

Aqueous solutions of monosodium glutamate may be sterilized by autoclaving. Monosodium glutamate should be stored in a tight container in a cool, dry place.

Source and Preparation

Monosodium glutamate is the monosodium salt of the naturally occurring L-form of glutamic acid. It is commonly manufactured by fermentation of carbohydrate sources such as sugar beet molasses.In general, sugar beet products are used in Europe and the USA. Other carbohydrate sources such as sugar cane and tapioca are used in Asia.

Applications

Monosodium glutamate is used in oral pharmaceutical formulations as a buffer and a flavor enhancer. For example, it is used with sugar to improve the palatability of bitter-tasting drugs and can reduce the metallic taste of iron-containing liquids. It has also been used in subcutaneous live vaccine injections such as measles, mumps, rubella and varicella-zoster live vaccine. However, the most widespread use of monosodium glutamate is as a flavor enhancer in food products. Typically, 0.2-0.9% is used in normally salted foods, although products such as soy protein can contain 10-30%. The use of monosodium glutamate in food products has been controversial owing to the apparently high number of adverse reactions attributed to the substance, which gives rise to the so-called‘Chinese Restaurant Syndrome'.

Safety

Monosodium glutamate is widely used in foods and oral pharmaceutical formulations. It is generally regarded as moderately toxic on ingestion or intravenous administration. Adverse effects include somnolence, hallucinations and distorted perceptions, headache, dyspnea, nausea or vomiting, and dermatitis. The lowest lethal oral dose in humans is reported to be 43 mg/kg.

Incompatibilities

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