Lactose, spray-dried

• BPLactose Monohydrate
• JPLactose Hydrate
• Ph. Eur.Lactose Monohydrate
• USP–NFLactose Monohydrate

Fast-Flo 316; FlowLac 90; FlowLac 100; Lactopress Spray-Dried; Pharmatose DCL 11; Pharmatose DCL 14; SuperTab 11SD; SuperTab 14SD

O-β-D-Galactopyranosyl-(1→4)-α-D-glucopyranose monohydrate, with a fraction of amorphous lactose · [—]

C12H22O11·H2O · 360.31

Diluent (filler)

Typical concentrations: — · Dosage forms: Solid

Used mainly as a filler-binder for direct compression of tablets, where its spherical particles give good flow and its amorphous fraction provides binding. It is also used in capsule filling and in sachets where good flow is needed.

A white to off-white, free-flowing powder of spherical agglomerates made up of fine α-lactose monohydrate crystals held together by amorphous lactose. It is odourless and slightly sweet.

Amorphous content

typically about 10–20%

Particle size (mean)

typically about 100–150 µm, depending on grade

Bulk density

≈ 0.6 g/cm³

Water content

about 4.5–5.5% w/w total (mainly water of crystallisation)

Solubility

freely soluble in water; practically insoluble in ethanol and ether

At high humidity the amorphous fraction can absorb water and crystallise, which reduces compactibility and may cause caking. It browns more readily than crystalline lactose, particularly in warm, damp conditions. Store in a well-closed container in a cool, dry place.

A reducing sugar that undergoes Maillard reaction with primary and secondary amines; the amorphous fraction reacts faster than crystalline lactose. Incompatible with strong oxidising agents.

Made by spray drying a suspension of fine α-lactose monohydrate crystals in a saturated lactose solution. The dissolved lactose dries rapidly to an amorphous glass that binds the crystals into spherical particles.

Regarded as non-toxic. As with other lactose grades, patients with lactase deficiency may be affected by large amounts.

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

Lactose is GRAS listed. Spray-dried lactose is included in the FDA Inactive Ingredient Database (oral capsules and tablets) and in non-parenteral medicines licensed in Europe.

Lactose, anhydrous; lactose monohydrate; lactose monohydrate and microcrystalline cellulose; lactose monohydrate and povidone.

Spray-dried lactose complies with the pharmacopoeial monographs for lactose monohydrate; suppliers state the amorphous content and particle size on the specification. Because its binding relies on the amorphous fraction, tablets should not be exposed to high humidity before packaging.