(Ph Eur monograph 1100)
Eugenol is 2-methoxy-4-(prop-2-enyl)phenol.
A colourless or pale yellow, clear liquid, darkening on exposure to air, with a
strong odour of clove, practically insoluble in water, freely soluble in alcohol (70 per
cent V/V), practically insoluble in glycerol, miscible with glacial acetic acid,
with alcohol, with ether, with fatty oils and with methylene chloride.
A, C, D.
complies with the test for refractive index (see Tests).
by infrared absorption spectrophotometry (2.2.24), comparing with the spectrum obtained
with eugenol CRS.
by thin-layer chromatography (2.2.27), using a TLC silica gel F254 plate R.
Dissolve 50 ml of the substance to be examined in alcohol R and dilute to 25 ml with the same solvent.
Dissolve 50 ml of eugenol
CRS in alcohol R and dilute
to 25 ml with the same solvent.
Apply to the plate 5 ml of each solution. Develop over a path
of 15 cm using a mixture of 10 volumes of ethyl acetate R and 90 volumes of toluene
R. Dry the plate in a current of cold air and examine in ultraviolet light at 254 nm.
The principal spot in the chromatogram obtained with the test solution is similar in
position and size to the principal spot in the chromatogram obtained with the reference
solution. Spray with anisaldehyde solution R. Heat at 100-105C for 10 min. The
principal spot in the chromatogram obtained with the test solution is similar in position,
colour and size to the principal spot in the chromatogram obtained with the reference
0.05 ml in 2 ml of alcohol R and add
0.1 ml of ferric chloride solution R1. A dark green colour is produced which
changes to yellowish-green within 10 min.
Relative density (2.2.5)
1.066 to 1.070.
Refractive index (2.2.6)
1.540 to 1.542.
Dimeric and oligomeric compounds
Dissolve 0.150 g of the substance to be examined in ethanol R and dilute to 100.0 ml with the same
solvent. The absorbance of the solution (2.2.25) at 330 nm is not greater than 0.25.
Examine by gas chromatography (2.2.28).
Dissolve 1.00 g of the substance to be examined in ethanol R and dilute to 5.0 ml with the same solvent.
Reference solution (a)
Dilute 1.0 ml of the test solution to 100.0 ml with ethanol R.
Reference solution (b)
Dissolve 50 mg of vanillin R in 1 ml of the test
solution and dilute to 5 ml with ethanol R.
The chromatographic procedure may be carried out using:
a fused-silica capillary column 30 m long and 0.25 mm in
internal diameter coated with a film of polymethylphenylsiloxane R (film thickness
helium for chromatography R as the
carrier gas at a flow rate of 1 ml/min,
a flame-ionisation detector,
a split ratio of 1:40,
Inject 1 ml of the test solution and 1 ml each of reference
solutions (a) and (b). The test is not valid unless in the chromatogram obtained with
reference solution (b), the relative retention time of the peak due to vanillin is at
least 1.1 with respect to the peak due to eugenol. Calculate the percentage content of
related substances from the areas of the peaks in the chromatogram obtained with the test
solution by the normalisation procedure; disregard the solvent peak and any peak with an
area less than 0.05 times that of the principal peak in the chromatogram obtained with
reference solution (a). The content of related substances with a relative retention time
greater than 2.0 in respect to the main peak is not greater than 1.0 per cent; the content
of any related substances is not greater than 0.5 per cent; the total content of related
substances is not greater than 3.0 per cent.
Dissolve 1 ml in 5 ml of dilute sodium hydroxide solution R
and add 30 ml of water R in a
stoppered test-tube. Examined immediately, the solution is yellow and clear (2.2.1).
Sulphated ash (2.4.14)
Not more than 0.1 per cent, determined on 1.0 g.
Store in a well-filled container, protected from light.
R1 = H, R2 = H, R3 = CH2-CH=CH2: 4-(prop-2-enyl)phenol,
R1 = CH3, R2 = OCH3, R3 = CH2-CH=CH2:
1,2-dimethoxy-4-(prop-2-enyl)benzene (eugenol methyl ether),
R1 = H, R2 = OCH3, R3 = CH=CH-CH3 (cis):
R1 = H, R2 = OCH3, R3 = CH=CH-CH3 (trans):
R1 = H, R2 = OCH3, R3 = CHO: 4-hydroxy-3-methoxybenzaldehyde (vanillin),
R1 = CO-CH3, R2 = OCH3, R3 = CH2-CH=CH2:
2-methoxy-4-(prop-2-enyl)phenyl acetate (acetyleugenol),
R1 = H, R2 = OCH3, R3 = CO-CH=CH2:
R1 = H, R2 = OCH3, R3 = CH=CH-CHO: (E)-3-(4-hydroxy-3-methoxyphenyl)prop-2-enal
further unknown dimeric compounds,
Action and use
Local anaesthetic used in dentistry.