Adipic Acid

Category

Flavoring agent

Molecular Formula

C6H10O4

Molecular Weight

146.14

Description

Adipic acid occurs as a white or almost white, odorless nonhygroscopic crystalline powder. The crystal structure of adipic acid is monoclinic holohedral.

UNII

76A0JE0FKJ

Chemical Name

Hexanedioic acid

CAS Number

124-04-9

Synonyms

Acidum adipicum; acifloctin; acinetten; adilactetten; asapic; 1, 4- butanedicarboxylic acid; E355; 1, 6-hexanedioic acid; Inipol DS.

Administration route

IM, IV, and vaginal

Dosage Form

IM, IV, and vaginal preparations

Stability and Storage Conditions

Adipic acid is normally stable but decomposes above boiling point.It should be stored in a tightly closed container in a cool, dry place, and should be kept away from heat, sparks, and open flame.

Source and Preparation

Adipic acid is prepared by nitric acid oxidation of cyclohexanol or cyclohexanone or a mixture of the two compounds. Recently, oxidation of cyclohexene with 30% aqueous hydrogen peroxide under organic solvent- and halide-free conditions has been proposed as an environmentally friendly alternative for obtaining colorless crystalline adipic acid.

Applications

Adipic acid is used as an acidifying and buffering agent in intramuscular, intravenous and vaginal formulations. It is also used in food products as a leavening, pH-controlling, or flavoring agent. Adipic acid has been incorporated into controlled-release formulation matrix tablets to obtain pH-independent release for both weakly basic and weakly acidic drugs. It has also been incorporated into the polymeric coating of hydrophilic monolithic systems to modulate the intragel pH, resulting in zero-order release of a hydrophilic drug.The disintegration at intestinal pH of the enteric polymer shellac has been reported to improve when adipic acid was used as a pore-forming agent without affecting release in the acidic media.Other controlled-release formulations have included adipic acid with the intention of obtaining a late-burst release profile.

Safety

Adipic acid is used in pharmaceutical formulations and food products. The pure form of adipic acid is toxic by the IP route, and moderately toxic by other routes. It is a severe eye irritant, and may cause occupational asthma.
LD50 (mouse, IP): 0.28 g/kg
LD50 (mouse, IV): 0.68 g/kg
LD50 (mouse, oral): 1.9 g/kg
LD50 (rat, IP): 0.28 g/kg
LD50 (rat, oral): >11 g/kg

Incompatibilities

Adipic acid is incompatible with strong oxidizing agents as well as strong bases and reducing agents. Contact with alcohols, glycols, aldehydes, epoxides, or other polymerizing compounds can result in violent reactions.