Pullulan

• JPPullulan
• USP–NFPullulan

α-1,4-; α-1,6-glucan; pullulane; E1204

Neutral, linear α-glucan made up of maltotriose units joined by α-(1→6) linkages (the glucose units within each maltotriose are α-(1→4) linked) · [9057-02-7]

(C6H10O5)n

Coating agent, film former

Typical concentrations: — · Dosage forms: Solid

Used mainly as a film-former: for hard capsule shells of non-animal origin, for orally dissolving films and strips, and in tablet coatings. Its films are clear, glossy, flexible, odourless and have very low oxygen permeability, which helps protect oxygen-sensitive contents. It is also used as a binder, as an edible coating and as a texturiser in foods and confectionery. Use levels depend on the application; in capsule shells and oral films it is the main structural polymer.

A white to off-white, odourless and tasteless powder. It dissolves readily in water to give viscous, non-gelling solutions.

Solubility

freely soluble in water; practically insoluble in ethanol and most other organic solvents

pH

about 5–7 (10% w/v aqueous solution)

Loss on drying

typically not more than 6%

Film properties

transparent, flexible and heat-sealable films with low oxygen permeability and good oil resistance

The powder is stable when stored in a well-closed container in a cool, dry place. It is not hydrolysed by most common amylases. Aqueous solutions support microbial growth and should be preserved or used promptly.

No significant incompatibilities have been reported; avoid strong oxidising agents.

Produced extracellularly by fermentation of a food-grade starch hydrolysate (syrup) with a non-toxigenic strain of the yeast-like fungus Aureobasidium pullulans. The cells are removed by filtration and the broth is decolourised, deionised and concentrated before the polysaccharide is dried and milled.

Considered non-toxic and non-irritant. It is digested only slowly and partly in the small intestine and is largely fermented in the colon, so large intakes may cause flatulence or abdominal discomfort.

Observe normal precautions for the quantity handled. Avoid generating dust; eye protection and a dust mask are recommended.

GRAS in the USA (the FDA has raised no questions on a GRAS notice). Accepted in Europe as a food additive (E1204). Pullulan capsules are used in licensed medicines and dietary supplements.

Dextran; hypromellose (for non-gelatin capsules); starch; maltodextrin.

Pullulan capsule shells are an option for vegetarian and vegan products and for fills that are sensitive to oxygen. Films and shells are fairly brittle at low humidity, so the moisture content of the shell should be controlled.