Acacia

cid3

49

Category

Emulsifying Agents; Stabilizing Agents; Suspending Agents; Tablet Binder; Viscosity-increasing Agents

Grade

Pharmceutical Excipients

Description

Acacia is available as white or yellowish-white thin flakes, spheroidal tears, granules, powder, or spray-dried powder. It is odorless and has a bland taste.

UNII

5C5403N26O

CAS Number

9000-5-1

Synonyms

Acaciae gummi; acacia gum; arabic gum; E414; gum acacia; gummi africanum; gum arabic; gummi arabicum; gummi mimosae; talhagum

Administration route

Oral; buccal or sublingual

Dosage Form

Oral preparations and buccal or sublingual tablets

Stability and Storage Conditions

Aqueous solutions are subject to bacterial or enzymatic degradation but may be preserved by initially boiling the solution for a short time to inactivate any enzymes present; microwave irradiation can also be used.Aqueous solutions may also be preserved by the addition of an antimicrobial preservative such as 0.1% w/v benzoic acid, 0.1% w/v sodium benzoate, or a mixture of 0.17% w/v methylparaben and 0.03% propylparaben. Powdered acacia should be stored in an airtight container in a cool, dry place.

Source and Preparation

Acacia is the dried gummy exudate obtained from the stems and branches of Acacia senegal. Willdenow or other related species of Acacia (Fam. Leguminosae) that grow mainly in the Sudan and Senegal regions of Africa. The bark of the tree is incised and the exudate allowed to dry on the bark. The dried exudate is then collected, processed to remove bark, sand, and other particulate matter, and graded. Various acacia grades differing in particle size and other physical properties are thus obtained. A spray-dried powder is also commercially available.

Applications

Acacia is mainly used in oral and topical pharmaceutical formulations as a suspending and emulsifying agent, often in combination with tragacanth. It is also used in the preparation of pastilles and lozenges, and as a tablet binder, although if used incautiously it can produce tablets with a prolonged disintegration time. Acacia has also been evaluated as a bioadhesive; and has been used in novel tablet formulations, and modified release tablets. Acacia is also used in cosmetics, confectionery, food products, and spray-dried flavors.

Safety

Acacia is used in cosmetics, foods, and oral and topical pharmaceutical formulations. Although it is generally regarded as an essentially nontoxic material, there have been a limited number of reports of hypersensitivity to acacia after inhalation or ingestion.Severe anaphylactic reactions have occurred following the parenteral administration of acacia and it is now no longer used for this purpose. The WHO has not set an acceptable daily intake for acacia as a food additive because the levels necessary to achieve a desired effect were not considered to represent a hazard to health. LD50 (hamster, oral): >18 g/kg LD50 (mouse, oral): >16 g/kg LD50 (rabbit, oral): 8.0 g/kg LD50 (rat, oral): >16 g/kg

Incompatibilities

Acacia is incompatible with a number of substances including amidopyrine, apomorphine, cresol, ethanol (95%), ferric salts, morphine, phenol, physostigmine, tannins, thymol, and vanillin. An oxidizing enzyme present in acacia may affect preparations containing easily oxidizable substances. However, the enzyme may be inactivated by heating at 1008C for a short time. Many salts reduce the viscosity of aqueous acacia solutions, while trivalent salts may initiate coagulation. Aqueous solutions carry a negative charge and will form coacervates with gelatin and other substances. In the preparation of emulsions, solutions of acacia are incompatible with soaps.