Edition: BP 2025 (Ph. Eur. 11.6 update)
(Ph. Eur. monograph 2584)
Ph Eur
DEFINITION
Mixture of mainly diesters of polymerised 12-hydroxystearic ((12Ξ)-hydroxyoctadecanoic) acid and
Macrogols (1444) obtained by esterification of macrogol with 12-hydroxystearic acid. The average number
of moles of ethylene oxide reacted per mole of substance is 30.
CHARACTERS
Appearance
Brownish-red, waxy mass.
Solubility
Practically insoluble in water, very soluble in methylene chloride and soluble in most aliphatic and aromatic
hydrocarbons.
mp
30 °C to 40 °C.
IDENTIFICATION
A. Infrared absorption spectrophotometry (2.2.24).
Comparison macrogol 30 dipolyhydroxystearate CRS.
B. Hydroxyl value (see Tests).
C. Saponification value (see Tests).
Macrogol 30 Dipolyhydroxystearate
TESTS
Acid value (2.5.1)
Maximum 10.0.
Hydroxyl value (2.5.3, Method A)
12 to 30.
Iodine value (2.5.4, Method A)
Maximum 10.0.
Peroxide value (2.5.5)
Maximum 5.0.
Saponification value (2.5.6)
125 to 145, determined on 2.0 g.
Use 30.0 mL of 0.5 M alcoholic potassium hydroxide, heat under reflux for 60 min and add 50 mL of
anhydrous ethanol R before carrying out the titration.
Water (2.5.12)
Maximum 1.0 per cent, determined on 0.50 g.
Sulfated ash (2.4.14)
Maximum 0.5 per cent.
Heat a silica crucible to redness for 30 min, allow to cool in a desiccator and weigh. Evenly distribute 1.0 g in
the crucible and weigh. Dry at 100-105 °C for 1 h and ignite in a muffle furnace at 600 ± 25 °C, until the
substance is thoroughly charred. Carry out the test for sulfated ash (2.4.14) on the residue obtained, starting
from “Moisten the substance to be examined…”.
STORAGE
In an airtight container.
