Names and synonyms
USP NF Name
Polyoxyl-32 stearate (type I) NF
EP Name
Macrogol-32 stearate (type I) EP
UNII Code (FDA)
33GX5WQC0M
Preferred Substance Name (FDA)
PEG-32 STEARATE
Handbook of Pharmaceutical Excipients
Polyoxylethylene stearates
Chemical description
Consists of PEG-32 (MW 1500) esters of palmitic (C16) and stearic (C18) acids
Key characteristics
Product form
Pellets
Melting range (°C)
46-50
HLB
12
CMC (mg/L, 25°C)
153 ± 31
Main functionalities
Solubilizer for low log P APIs and bioavailability enhancer. Single excipient formulation system: self-emulsifies in aqueous fluid into micellar solution—LFCS Type IV. Use in melt processes (granulation, extrusion), granulation, and compression. Wetting agent. Safety of use is inferred by precedence of use in approved pharmaceutical products.
Main formulation technologies
Self-emulsifying lipid formulation for oral applications. Melt processes: granulation, extrusion, capsule molding, and compression. Wet granulation and compression.
