Azithromycin(阿奇霉素)EP9.3

System suitability:reference solution(b):
–resolution:minimum2.5between the peaks due to
impurity B and atropine.
Limits:
–correction factors:for the calculation of content,multiply
the peak areas of the following impurities by the
corresponding correction factor:impurity A=0.6;
impurity C=0.6;
–impurities E,H:for each impurity,not more than3times
the area of the principal peak in the chromatogram
obtained with reference solution(a)(0.3per cent);
–impurities A,B,C,D,F,G:for each impurity,not more than
twice the area of the principal peak in the chromatogram
obtained with reference solution(a)(0.2per cent);
–unspecified impurities:for each impurity,not more than the
area of the principal peak in the chromatogram obtained
with reference solution(a)(0.10per cent);
–total:not more than5times the area of the principal peak
in the chromatogram obtained with reference solution(a)
(0.5per cent);
–disregard limit:0.5times the area of the principal peak in
the chromatogram obtained with reference solution(a)
(0.05per cent).
Water(2.5.12):2.0per cent to4.0per cent,determined on
0.500g.
Sulfated ash(2.4.14):maximum0.1per cent,determined on
1.0g.
ASSAY
Dissolve0.500g in30mL of anhydrous acetic acid R,warming
if necessary.Cool the solution.Titrate with0.1M perchloric
acid,determining the end-point potentiometrically(2.2.20).
1mL of0.1M perchloric acid is equivalent to67.68mg
of C
34
H
48
N
2
O
10
S.
STORAGE
Protected from light.
IMPURITIES
Specified impurities:A,B,C,D,E,F,G,
H.
A.(1R,3r,5S)-8-methyl-8-azabicyclo[3.2.1]oct-3-yl
2-phenylpropenoate
(apoatropine),
B.(1R,3r,5S)-8-azabicyclo[3.2.1]oct-3-yl(2RS)-3-hydroxy-2-
phenylpropanoate
(noratropine),
C.(2RS)-3-hydroxy-2-phenylpropanoic acid(tropic
acid),
D.(1R,3S,5R,6RS)-6-hydroxy-8-methyl-8-azabicyclo-
[3.2.1]oct-3-yl(2S)-3-hydroxy-2-phenylpropanoate
(6-hydroxyhyoscyamine),
E.(1S,3R,5S,6RS)-6-hydroxy-8-methyl-8-azabicy-
clo[3.2.1]oct-3-yl(2S)-3-hydroxy-2-phenylpropanoate
(7-hydroxyhyoscyamine),
F.(1R,2R,4S,5S,7s)-9-methyl-3-oxa-9-azatricy-
clo[3.3.1.02,4]non-7-yl(2S)-3-hydroxy-2-phenylpropanoate
(hyoscine),
G.(1R,3r,5S)-8-methyl-8-azabicyclo[3.2.1]oct-3-yl
(2RS)-2-hydroxy-3-phenylpropanoate(littorine).
H.unknown structure.
01/2018:1649
AZITHROMYCIN
Azithromycinum
C
38
H
72
N
2
O
12
,x H
2
O
with x=1or2
M
r
749(anhydrous substance)
Azithromycin monohydrate:[121470-24-4]
Azithromycin dihydrate:[117772-70-0]
DEFINITION
(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-13-[(2,6-Dideoxy-3-
C-methyl-3-O-methyl-α-L-ribo-hexopyranosyl)oxy]-2-ethyl-
3,4,10-trihydroxy-3,5,6,8,10,12,14-heptamethyl-11-[[3,4,6-
trideoxy-3-(dimethylamino)-β-D-xylo-hexopyranosyl]oxy]-1-
oxa-6-azacyclopentadecan-15-one.The degree of hydration is
1or2.
Semi-synthetic product derived from a fermentation product.
Content:96.0per cent to102.0per cent(anhydrous substance). CHARACTERS
Appearance:white or almost white powder.
Solubility:practically insoluble in water,freely soluble in anhydrous ethanol and in methylene chloride. IDENTIFICATION
Infrared absorption spectrophotometry(2.2.24). Comparison:azithromycin CRS.
If the spectra obtained in the solid state show differences, prepare further spectra using90g/L solutions in methylene chloride R.
TESTS
Solution S.Dissolve0.500g in anhydrous ethanol R and dilute to50.0mL with the same solvent.
Appearance of solution.Solution S is clear(2.2.1)and colourless(2.2.2,Method II).
pH(2.2.3):9.0to11.0.
Dissolve0.100g in25.0mL of methanol R and dilute to 50.0mL with carbon dioxide-free water R.
Specific optical rotation(2.2.7):−49to−45(anhydrous substance),determined on solution S.
Related substances.Liquid chromatography(2.2.29). Solvent mixture.Prepare a1.73g/L solution of ammonium dihydrogen phosphate R adjusted to pH10.0with ammonia R. Transfer350mL of this solution to a suitable container.Add 300mL of acetonitrile R1and350mL of methanol R1.Mix well.
Test solution.Dissolve0.200g of the substance to be examined in the solvent mixture and dilute to25.0mL with the solvent mixture.
Reference solution(a).Dilute1.0mL of the test solution to 100.0mL with the solvent mixture.
Reference solution(b).Dissolve the contents of a vial of azithromycin for system suitability CRS(containing impurities F,H and J)in1.0mL of the solvent mixture and sonicate for 5min.
Reference solution(c).Dissolve8.0mg of azithromycin for peak identification CRS(containing impurities A,B,C,E,F,G, I,J,L,M,N,O and P)in1.0mL of the solvent mixture. Column:
–size:l=0.25m,Ø=4.6mm;
–stationary phase:end-capped octadecylsilyl amorphous organosilica polymer for mass spectrometry R(5μm);
–temperature:60°C.
Mobile phase:
–mobile phase A:1.80g/L solution of anhydrous disodium hydrogen phosphate R adjusted to pH8.9with dilute
phosphoric acid R or with dilute sodium hydroxide
solution R;
–mobile phase B:methanol R1,acetonitrile R1(250:750V/V);
Time (min)Mobile phase A
(per cent V/V)
Mobile phase B
(per cent V/V)
0-2550→4550→55
25-3045→4055→60
30-8040→2560→75
80-8125→5075→50
81-935050 Flow rate:1.0mL/min.
Detection:spectrophotometer at210nm. Injection:50μL.Identification of impurities:use the chromatogram supplied with azithromycin for peak identification CRS and the chromatogram obtained with reference solution(c)to identify the peaks due to impurities A,B,C,E,F,G,I,J,L,M,N,O and P;use the chromatogram supplied with azithromycin for system suitability CRS and the chromatogram obtained with reference solution(b)to identify the peak due to impurity H. Relative retention with reference to azithromycin (retention time=45-50min):impurity L=about0.29; impurity M=about0.37;impurity E=about0.43; impurity F=about0.51;impurity D=about0.54;
impurity J=about0.54;impurity Q=about0.54;
impurity I=about0.61;impurity C=about0.73;
impurity N=about0.76;impurity H=about0.79; impurity A=about0.83;impurity P=about0.92;
impurity O=about1.23;impurity G=about1.26; impurity B=about1.31.
System suitability:reference solution(b):
–peak-to-valley ratio:minimum1.4,where H p=height above the baseline of the peak due to impurity J and
H
v
=height above the baseline of the lowest point of the curve separating this peak from the peak due to impurity F. Limits:
–correction factors:for the calculation of content, multiply the peak areas of the following impurities by
the corresponding correction factor:impurity F=0.3;
impurity G=0.2;impurity H=0.1;impurity L=2.3;
impurity M=0.6;impurity N=0.7;
–impurity B:not more than twice the area of the principal peak in the chromatogram obtained with reference
solution(a)(2.0per cent);
–impurities A,C,E,F,H,I,L,M,N,O,P:for each impurity, not more than0.5times the area of the principal peak in the chromatogram obtained with reference solution(a)
(0.5per cent);
–sum of impurities D,J and Q:not more than0.5times the area of the principal peak in the chromatogram obtained with reference solution(a)(0.5per cent);
–impurity G:not more than0.2times the area of the principal peak in the chromatogram obtained with
reference solution(a)(0.2per cent);
–any other impurity:for each impurity,not more than
0.2times the area of the principal peak in the chromatogram
obtained with reference solution(a)(0.2per cent);
–total:not more than3times the area of the principal peak in the chromatogram obtained with reference solution(a)
(3.0per cent);
–disregard limit:0.1times the area of the principal peak in the chromatogram obtained with reference solution(a)
(0.1per cent);disregard the peaks eluting before impurity L
and after impurity B.
Water(2.5.12):1.8per cent to6.5per cent,determined on 0.200g.
Sulfated ash(2.4.14):maximum0.2per cent,determined on 1.0g.
ASSAY
Liquid chromatography(2.2.29).
Solution A.Mix60volumes of acetonitrile R1and40volumes of a6.7g/L solution of dipotassium hydrogen phosphate R adjusted to pH8.0with phosphoric acid R.
Test solution.Dissolve53.0mg of the substance to be examined in2mL of acetonitrile R1and dilute to100.0mL with solution A.
Reference solution(a).Dissolve53.0mg of azithromycin CRS in2mL of acetonitrile R1and dilute to100.0mL with solution A.
Reference solution(b).Dissolve5mg of the substance to be
examined and5mg of azithromycin impurity A CRS in0.5mL
of acetonitrile R1and dilute to10mL with solution A.
Column:
–size:l=0.25m,Ø=4.6mm;
–stationary phase:octadecylsilyl vinyl polymer for
chromatography R(5μm);
–temperature:40°C.
Mobile phase:mix60volumes of acetonitrile R1and
40volumes of a6.7g/L solution of dipotassium hydrogen
phosphate R adjusted to pH11.0with a560g/L solution of
potassium hydroxide R.
Flow rate:1.0mL/min.
Detection:spectrophotometer at210nm.
Injection:10μL.
Run time:1.5times the retention time of azithromycin.
Retention time:azithromycin=about10min.
System suitability:reference solution(b):
–resolution:minimum3.0between the peaks due to
impurity A and azithromycin.
Calculate the percentage content of C
38
H
72
N
2
O
12
taking into
account the assigned content of azithromycin CRS.
STORAGE
In an airtight container.
IMPURITIES
Specified impurities:A,B,C,D,E,F,G,H,I,J,L,M,N,O,P,Q.
Other detectable impurities(the following substances would,
if present at a sufficient level,be detected by one or other of
the tests in the monograph.They are limited by the general
acceptance criterion for other/unspecified impurities and/or
by the general monograph Substances for pharmaceutical
use(2034).It is therefore not necessary to identify these
impurities for demonstration of compliance.See also5.10.
Control of impurities in substances for pharmaceutical use):K
.
A.
6-demethylazithromycin,
B.3-deoxyazithromycin(azithromycin
B),
C.3"-O-demethylazithromycin(azithromycin
C),
D.14-demethyl-14-(hydroxymethyl)azithromycin
(azithromycin
F),
E.3'-(N,N-didemethyl)azithromycin
(aminoazithromycin),
F.3'-N-demethyl-3'-N
-formylazithromycin,
G.3'-N-demethyl-3'-N-[(4-methylphenyl)sulfonyl]-
azithromycin,
H.3'-N -[[4-(acetylamino)phenyl]sulfonyl]-3'-N -
demethylazithromycin,
I.3'-N
-demethylazithromycin,
J.13-O
-decladinosylazithromycin,
K.C 14,1"-epoxyazithromycin (azithromycin
E),
L.azithromycin 3'-N
-oxide,
M.3'-(N ,N -didemethyl)-3'-N
-formylazithromycin,
N.3'-de(dimethylamino)-3'
-oxoazithromycin,
O.2-desethyl-2-propylazithromycin,
P .unknown
structure,
Q.3'-N -[[4-(acetylamino)phenyl]sulfonyl]-3'-(N ,N -didemethyl)azithromycin.。