Arginine

• BPArginine
• JPL-Arginine
• Ph. Eur.Arginine
• USP–NFArginine

L-arginine; argininum; (S)-2-amino-5-guanidinopentanoic acid; 2-amino-5-guanidinovaleric acid

(2S)-2-Amino-5-guanidinopentanoic acid · [74-79-3]

UNII 94ZLA3W45F · PubChem CID 6322

C6H14N4O2 · 174.20

pH adjuster, buffering agent, Stabiliser, lyoprotectant

Typical concentrations: — · Dosage forms: Sterile (parenteral/ophthalmic)

Used in parenteral protein and peptide formulations to suppress aggregation and to reduce the viscosity of high-concentration antibody solutions, and as a buffering and alkalising agent. It is also used as a counter-ion to form soluble salts of acidic drugs (for example ibuprofen arginine), as a stabiliser in freeze-dried products, and as an active amino acid in nutrition.

White or almost white crystals or crystalline powder, practically odourless, with a slightly bitter taste.

pKa

≈ 2.2 (carboxyl), ≈ 9.0 (α-amino), ≈ 12.5 (guanidino)

Isoelectric point

≈ 10.8

pH

strongly alkaline in aqueous solution (about pH 10.5–12 for a 10% solution)

Solubility

freely soluble in water; very slightly soluble in ethanol; practically insoluble in ether

Stable in the solid state. Its strongly alkaline solutions absorb carbon dioxide from the air. Store in an airtight container, protected from light.

Incompatible with strong oxidising agents. As a primary amine it can undergo Maillard reactions with reducing sugars, and its high pH can degrade base-sensitive drugs and excipients.

Produced mainly by microbial fermentation (for example with Corynebacterium glutamicum) followed by isolation and crystallisation; older methods used hydrolysis of proteins.

A naturally occurring amino acid that is well tolerated at excipient levels. Large intravenous doses, as used therapeutically or diagnostically, can cause hyperkalaemia, hyperchloraemic acidosis (with the hydrochloride) and local irritation if extravasated.

Observe normal precautions for the quantity handled. Eye protection and gloves are recommended; concentrated solutions are irritant because of their high pH.

Included in the FDA Inactive Ingredient Database (intravenous and subcutaneous injections and oral preparations) and in parenteral and non-parenteral medicines licensed in Europe.

Arginine hydrochloride; histidine; lysine; glycine.

In biologic formulations arginine is often used as its hydrochloride, or with an acidic counter-ion such as glutamate, so that it can be included at stabilising concentrations without raising the pH.