Maltose

• JPMaltose Hydrate
• USP–NFMaltose

Malt sugar; maltobiose; maltose monohydrate; Advantose 100; Sunmalt

4-O-α-D-Glucopyranosyl-β-D-glucopyranose monohydrate · [69-79-4]

C12H22O11·H2O · 360.31

Sweetening agent

Typical concentrations: — · Dosage forms: Solid, Liquid

Used as a sweetener and as a tablet diluent and binder, including spray-dried grades for direct compression. It is used as a stabiliser and tonicity agent in some parenteral protein products (for example intravenous immunoglobulins), as a lyoprotectant in freeze-dried products, and as a carbohydrate source in some intravenous infusions.

White crystals or crystalline powder, odourless, with a mildly sweet taste; its sweetness is roughly a third of that of sucrose.

Melting point

about 102–103 °C (monohydrate)

Solubility

freely soluble in water; very slightly soluble in ethanol; practically insoluble in ether

Specific rotation

about +126° to +131° (at equilibrium, anhydrous basis)

Reducing sugar

yes; solutions show mutarotation

Stable when stored dry. Aqueous solutions show mutarotation and can support microbial growth. Store in a well-closed container in a cool, dry place.

As a reducing sugar it can undergo Maillard reactions with primary and secondary amines, including amino acids and proteins (glycation). Incompatible with strong oxidising agents.

Produced by enzymatic hydrolysis of starch with β-amylase (often with a debranching enzyme), followed by purification and crystallisation or spray drying.

Hydrolysed to glucose and regarded as non-toxic. Important: parenteral maltose (for example in some immunoglobulin products) can give falsely high blood glucose readings with glucose-meter strips that use glucose dehydrogenase–pyrroloquinoline quinone (GDH-PQQ), which has led to inappropriate insulin dosing.

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

Monographs in the USP–NF and JP. Used in oral solid products and, in some countries, in parenteral protein formulations and infusions.

Lactose; maltitol; sucrose; trehalose; maltodextrin.

For protein stabilisation, non-reducing sugars such as sucrose or trehalose avoid the glycation risk of maltose. Product labelling for maltose-containing parenterals should warn about interference with GDH-PQQ glucose monitoring.