Fluconazole EUROPEAN PHARMACOPOEIA 6.

— disregard limit : 0.05 times the area of the principal peak

in the chromatogram obtained with reference solution (b)
(0.05 per cent).
N,N-Dimethylaniline (2.4.26, Method B) : maximum 20 ppm.
2-Ethylhexanoic acid (2.4.28) : maximum 0.8 per cent m/m.
Water (2.5.12) : 3.0 per cent to 4.5 per cent, determined on
0.300 g.
Pyrogens (2.6.8). If intended for use in the manufacture D. 3-(2-chloro-6-fluorophenyl)-5-methylisoxazole-4-carboxylic
of parenteral dosage forms without a further appropriate acid,
procedure for the removal of pyrogens, it complies with
the test. Inject per kilogram of the rabbit’s mass 1 ml of a
solution in water for injections R containing 20 mg of the
substance to be examined per millilitre.

ASSAY
Liquid chromatography (2.2.29) as described in the test for
related substances with the following modifications.
Injection : test solution (b) and reference solution (a).
System suitability : reference solution (a) :
— repeatability : maximum relative standard deviation of E. (2S,5R,6R)-6-[[[(2S,5R,6R)-6-[[[3-(2-chloro-6-
1.0 per cent after 6 injections. fluorophenyl)-5-methylisoxazol-4-yl]carbonyl]amino]-
Calculate the percentage content of C19H16ClFN3NaO5S from 3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-
the declared content of flucloxacillin sodium CRS. 2-yl]carbonyl]amino]-3,3-dimethyl-7-oxo-4-thia-1-
azabicyclo[3.2.0]heptane-2-carboxylic acid.
STORAGE
In an airtight container, at a temperature not exceeding
25 °C. If the substance is sterile, store in a sterile, airtight, 01/2008:2287
tamper-proof container. corrected 6.0

IMPURITIES FLUCONAZOLE
Specified impurities : A, B, C, D, E.
Fluconazolum

A. R = CO2H : (4S)-2-[carboxy[[[3-(2-chloro-6-fluorophenyl)-
5-methylisoxazol-4-yl]carbonyl]amino]methyl]-5,5-
dimethylthiazolidine-4-carboxylic acid (penicilloic acids C13H12F2N6O Mr 306.3
of flucloxacillin), [86386-73-4]

DEFINITION
B. R = H : (2RS,4S)-2-[[[[3-(2-chloro-6-fluorophenyl)- 2-(2,4-Difluorophenyl)-1,3-bis(1H-1,2,4-triazol-1-yl)propan-
5-methylisoxazol-4-yl]carbonyl]amino]methyl]-5,5- 2-ol.
dimethylthiazolidine-4-carboxylic acid (penilloic acids of Content : 99.0 per cent to 101.0 per cent (dried substance).
flucloxacillin),
CHARACTERS
Appearance : white or almost white, hygroscopic, crystalline
powder.
Solubility : slightly soluble in water, freely soluble in
methanol, soluble in acetone.
It shows polymorphism (5.9).

IDENTIFICATION
C. (2S,5R,6R)-6-amino-3,3-dimethyl-7-oxo-4-thia-
1-azabicyclo[3.2.0]heptane-2-carboxylic acid Infrared absorption spectrophotometry (2.2.24).
(6-aminopenicillanic acid), Comparison : fluconazole CRS.

1900 See the information section on general monographs (cover pages)

EUROPEAN PHARMACOPOEIA 6.0 Fluconazole

If the spectra obtained in the solid state show differences, — impurity B : not more than the area of the principal peak
dissolve the substance to be examined and the reference in the chromatogram obtained with reference solution (c)
substance separately in the minimum volume of methylene (0.3 per cent) ;
chloride R, evaporate to dryness on a water-bath and record
— impurity C : not more than the area of the corresponding
new spectra using the residues.
peak in the chromatogram obtained with reference
solution (d) (0.1 per cent) ;
TESTS
— unspecified impurities : for each impurity, not more
Appearance of solution. The solution is clear (2.2.1) and than 0.2 times the area of the principal peak in the
colourless (2.2.2, Method II). chromatogram obtained with reference solution (a)
Dissolve 1.0 g in methanol R and dilute to 20 ml with the (0.10 per cent) ;
same solvent. — total : not more than 1.2 times the area of the principal
Related substances. Liquid chromatography (2.2.29). peak in the chromatogram obtained with reference
solution (a) (0.6 per cent) ;
Test solution. Dissolve 0.100 g of the substance to be
examined in the mobile phase, sonicate if necessary, and — disregard limit : 0.1 times the area of the principal peak
dilute to 10.0 ml with the mobile phase. in the chromatogram obtained with reference solution (a)
(0.05 per cent).
Reference solution (a). Dilute 5.0 ml of the test solution
to 100.0 ml with the mobile phase. Dilute 1.0 ml of this Heavy metals (2.4.8) : maximum 10 ppm.
solution to 10.0 ml with the mobile phase. Dissolve 2.0 g in a mixture of 15 volumes of water R and
Reference solution (b). Dissolve 5 mg of fluconazole for 85 volumes of methanol R and dilute to 20.0 ml with the
peak identification CRS (containing impurity A) in the same mixture of solvents. 12 ml of the solution complies with
mobile phase, sonicate if necessary, and dilute to 10 ml with test B. Prepare the reference solution using lead standard
the mobile phase. solution (1 ppm Pb) R.
Reference solution (c). Dissolve 3.0 mg of fluconazole Loss on drying (2.2.32) : maximum 0.5 per cent, determined
impurity B CRS in the mobile phase, sonicate if necessary on 1.000 g by drying in an oven at 105 °C.
and, dilute to 100.0 ml with the mobile phase. Sulphated ash (2.4.14) : maximum 0.1 per cent, determined
on 1.0 g.
Reference solution (d). Dissolve 2.0 mg of fluconazole
impurity C CRS in the mobile phase and dilute to 20.0 ml
with the mobile phase. To 1.0 ml of this solution add 1.0 ml ASSAY
of the test solution and dilute to 10.0 ml with the mobile Dissolve 0.125 g in 60 ml of anhydrous acetic acid R. Titrate
phase. with 0.1 M perchloric acid, determining the end-point
Column : potentiometrically (2.2.20).
— size : l = 0.15 m, Ø = 4.6 mm ; 1 ml of 0.1 M perchloric acid is equivalent to 15.32 mg
of C13H12F2N6O.
— stationary phase : octadecylsilyl silica gel for
chromatography R1 (5 µm) ;
STORAGE
— temperature : 40 °C.
In an airtight container.
Mobile phase : acetonitrile R, 0.63 g/l solution of
ammonium formate R (14:86 V/V). IMPURITIES
Flow rate : 1.0 ml/min. Specified impurities : A, B, C.
Detection : spectrophotometer at 260 nm. Other detectable impurities (the following substances would,
Injection : 20 µl. if present at a sufficient level, be detected by one or other of
the tests in the monograph. They are limited by the general
Run time : 3.5 times the retention time of fluconazole. acceptance criterion for other/unspecified impurities and/or
Identification of impurities : use the chromatogram by the general monograph Substances for pharmaceutical
supplied with fluconazole for peak identification CRS and use (2034). It is therefore not necessary to identify these
the chromatogram obtained with reference solution (b) to impurities for demonstration of compliance. See also 5.10.
identify the peak due to impurity A ; use the chromatogram Control of impurities in substances for pharmaceutical
obtained with reference solution (c) to identify the peak due use) : D, E, F, G, H, I.
to impurity B and the chromatogram obtained with reference
solution (d) to identify the peak due to impurity C.
Relative retention with reference to fluconazole
(retention time = about 11 min) : impurity B = about 0.4 ;
impurity A = about 0.5 ; impurity C = about 0.8.
System suitability : reference solution (d) :
— resolution : minimum 3.0 between the peaks due to
impurity C and fluconazole.
Limits :
— impurity A : not more than 0.8 times the area of the
principal peak in the chromatogram obtained with A. (2RS)-2-(2,4-difluorophenyl)-1-(1H-1,2,4-triazol-1-yl)-3-(4H-
reference solution (a) (0.4 per cent) ; 1,2,4-triazol-4-yl)propan-2-ol,

General Notices (1) apply to all monographs and other texts 1901
Flucytosine EUROPEAN PHARMACOPOEIA 6.0

I. 4-amino-1-[(2RS)-2-(2,4-difluorophenyl)-2-hydroxy-3-
(1H-1,2,4-triazol-1-yl)propyl]-4H-1,2,4-triazolium.
B. 2-[2-fluoro-4-(1H-1,2,4-triazol-1-yl)phenyl]-1,3-bis(1H-1,2,4-
triazol-1-yl)propan-2-ol,

01/2008:0766
corrected 6.0

FLUCYTOSINE
Flucytosinum
C. 1,1′-(1,3-phenylene)di-1H-1,2,4-triazole,

C4H4FN3O Mr 129.1
[2022-85-7]
DEFINITION
Flucytosine contains not less than 98.5 per cent and
D. 2-(4-fluorophenyl)-1,3-bis(1H-1,2,4-triazol-1-yl)propan-2-ol, not more than the equivalent of 101.0 per cent of
4-amino-5-fluoropyrimidin-2(1H)-one, calculated with
reference to the dried substance.
CHARACTERS
A white or almost white, crystalline powder, sparingly
soluble in water, slightly soluble in ethanol.
IDENTIFICATION
First identification : A.
E. 1-[(6RS)-4,6-difluoro-6-(1H-1,2,4-triazol-1-yl)cyclohexa-1,4-
dienyl]ethanone, Second identification : B, C, D.
A. Examine by infrared absorption spectrophotometry
(2.2.24), comparing with the spectrum obtained with
flucytosine CRS.
B. Examine the chromatograms obtained in the test
for related substances. The principal spot in the
chromatogram obtained with test solution (b) is
similar in position and size to the principal spot in the
chromatogram obtained with reference solution (a).
C. Mix about 5 mg with 45 mg of heavy magnesium oxide R
F. R = OH : (2RS)-2-(2,4-difluorophenyl)-3-(1H-1,2,4-triazol- and ignite in a crucible until an almost white residue is
1-yl)propane-1,2-diol, obtained (usually less than 5 min). Allow to cool, add 1 ml
of water R, 0.05 ml of phenolphthalein solution R1 and
H. R = Br : (2RS)-1-bromo-2-(2,4-difluorophenyl)-3-(1H-1,2,4- about 1 ml of dilute hydrochloric acid R to render the
triazol-1-yl)propan-2-ol, solution colourless. Filter and add to the filtrate a freshly
prepared mixture of 0.1 ml of alizarin S solution R and
0.1 ml of zirconyl nitrate solution R. Mix, allow to stand
for 5 min and compare the colour of the solution with
that of a blank prepared in the same manner. The colour
of the solution changes from red to yellow.
D. To 5 ml of solution S (see Tests) add 0.15 ml of bromine
G. [3-[[(2RS)-2-(2,4-difluorophenyl)oxiran-2-yl]methyl]- water R and shake. The colour of the solution is
1H-1,2,4-triazol-1-yl]methanesulphonic acid, discharged.

1902 See the information section on general monographs (cover pages)