Dextrin

• BPDextrin
• JPDextrin
• Ph. Eur.Dextrin
• USP–NFDextrin

British gum; canary dextrin; dextrinum; pyrodextrin; starch gum; white dextrin; yellow dextrin

Dextrin (partially hydrolysed starch) · [9004-53-9]

(C6H10O5)n·xH2O · variable

Binder, Diluent (filler)

Typical concentrations: — · Dosage forms: Solid

Used as a binder (as an aqueous paste or solution) and diluent in tablets and capsules, as an adhesive and plasticising component of sugar-coating syrups, and as a thickening and stiffening agent in suspensions, pastes and topical preparations. It is also used widely as an adhesive and in foods. Concentrations depend on the role and are chosen empirically.

A white, pale yellow or brown powder or granules with a slight characteristic odour. The colour and properties depend on how the starch was converted: white dextrins are pale, while yellow dextrins and British gums are darker.

Solubility

readily soluble in boiling water, giving a mucilaginous solution; slowly soluble in cold water (white dextrins less soluble than yellow); practically insoluble in ethanol and ether

Types

white dextrins, yellow (canary) dextrins and British gums, differing in degree of conversion, colour, solubility and solution viscosity

Solution viscosity

lower than that of starch pastes; highly converted yellow dextrins give concentrated solutions of relatively low viscosity

Stable under normal storage conditions. Store in a well-closed container in a cool, dry place. Aqueous solutions are susceptible to microbial spoilage unless preserved.

Incompatible with strong oxidising agents. Its reducing end groups can take part in Maillard reactions with amine drugs, although to a lesser extent than reducing sugars.

Made by heating dry starch (usually maize or potato), with or without a small amount of acid. Mild heating with acid gives white dextrins, longer heating at higher temperature gives yellow dextrins, and high temperature with little or no acid gives British gums.

Digested and absorbed like starch and regarded as non-toxic and non-irritant.

Observe normal precautions for the quantity handled. Avoid dust, which may irritate the eyes; fine starch-derived dusts can be explosive.

GRAS listed. Included in the FDA Inactive Ingredient Database (oral capsules, suspensions and tablets) and in non-parenteral medicines licensed in Europe.

Cyclodextrins; dextrates; maltodextrin; starch; pregelatinised starch.

Dextrin is a broad family rather than a single material, so the pharmacopoeial grade and supplier specification should be fixed for reproducible binder behaviour. Maltodextrin, made by enzymatic or acid hydrolysis in solution, is generally preferred today as a binder and filler because of its more consistent quality.