Pregelatinized starch

• BPPregelatinised Starch
• Ph. Eur.Starch, Pregelatinised
• USP–NFPregelatinized Starch

Compressible starch; Lycatab PGS; pregelatinised maize starch; Spress B820; Starch 1500; amylum pregelificatum

Pregelatinised starch · [9005-25-8]

(C6H10O5)n, n ≈ 300–1000

Binder, Diluent (filler), Disintegrant

Typical concentrations: 5–20% binder · 5–10% disintegrant · Dosage forms: Solid

Used in oral capsules and tablets as a binder, diluent and disintegrant; partially pregelatinised grades flow and compress well enough for direct compression and also act as a lubricant to some degree. Fully pregelatinised starch is used as a binder and thickening agent. Typical concentrations: capsule diluent 5–75%; tablet binder in direct compression 5–20%; tablet binder in wet granulation 5–10%; tablet disintegrant 5–10%.

Starch (usually maize, but also potato or rice) that has been chemically unmodified but physically processed to rupture all or part of the starch granules. It is a moderately coarse to fine, white to off-white powder, odourless and with a slight characteristic taste. Partially pregelatinised grades contain a cold-water-soluble fraction together with intact granules.

Cold-water-soluble fraction

about 10–20% for partially pregelatinised grades; much higher for fully pregelatinised grades

pH

4.5–7.0 (10% w/v aqueous dispersion)

Moisture content

typically about 10–14% w/w

Solubility

practically insoluble in organic solvents; partly soluble or swelling in cold water, depending on the degree of pregelatinisation

Stable but hygroscopic. Store in a well-closed container in a cool, dry place.

Incompatible with strong oxidising agents. Forms coloured inclusion compounds with iodine.

An aqueous slurry of starch is heated to gelatinise the granules and then dried, for example on heated drums or by spray-drying, and milled. Partially pregelatinised starch is produced by mechanical and thermal processing of moist starch so that only part of the granules is ruptured.

Starch is a normal food and pregelatinised starch is regarded as non-toxic and non-irritant. Excessive dust should be avoided, and rare hypersensitivity to starch of particular botanical origin is possible.

Observe normal precautions for the quantity handled. Eye protection and a dust mask are recommended; starch dust can form explosive mixtures with air.

Included in the FDA Inactive Ingredient Database (oral capsules, suspensions and tablets; vaginal preparations) and in non-parenteral medicines licensed in Europe. As a physically treated starch it is regarded as a food ingredient rather than a modified-starch food additive.

Maize starch; potato starch; sodium starch glycolate; starch, sterilisable maize.

Partially pregelatinised starch is sensitive to over-lubrication: magnesium stearate can markedly reduce tablet hardness, so its level is kept low (often about 0.25% or less) or stearic acid is used instead. Its moisture content can affect moisture-sensitive drugs and should be considered in stability studies.