Paclitaxel
(pak'' li tax' el).
Click to View Image
C47H51NO14 853.91
Benzenepropanoic acid, -(benzoylamino)--hydroxy-, 6,12b-bis(acetyloxy)-12-(benzoyloxy)-2a,3,4,4a,5,6,9,10,11,12,12a,12b-dodecahydro-4,11-dihydroxy-4a,8,13,13-tetramethyl-5-oxo-7,11-methano-1H-cyclodeca[3,4]benz[1,2-b]oxet-9-yl ester, [2aR-[2a,4,4a,6,9(R*,S*),11,12,12a,12b]]-.
(2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-1,2a,3,4,4a,6,9,10,11,12,12a,12b-Dodecahydro-4,6,9,11,12,12b-hexahydroxy-4a,8,13,13-tetramethyl-7,11-methano-5H-cyclodeca[3,4]-benz[1,2-b]oxet-5-one 6,12b-diacetate, 12-benzoate, 9-ester with (2R,3S)-N-benzoyl-3-phenylisoserine [33069-62-4].
» Paclitaxel contains not less than 97.0 percent and not more than 102.0 percent of C47H51NO14, calculated on the anhydrous, solvent-free basis.
[Caution—Paclitaxel is cytotoxic. Great care should be taken to prevent inhaling particles of Paclitaxel and exposing the skin to it. ]
Packaging and storage— Preserve in tight, light-resistant containers, and store at controlled room temperature.
Labeling— The labeling indicates the type of process used to produce the material and the Related compounds test with which the material complies.
USP Reference standards 11
USP Endotoxin RS
USP Paclitaxel RS Click to View Structure
USP Paclitaxel Related Compound A RS
Cephalomannine.
USP Paclitaxel Related Compound B RS
10-Deacetyl-7-epipaclitaxel.
USP Paclitaxel Impurity Mixture RS
Mixture of paclitaxel and the following related compounds: propyl analog, cephalomannine, sec-butyl analog, n-butyl analog, benzyl analog, baccatin VI, pentyl analog, and 7-epipaclitaxel.
Identification—
B: The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.
Specific rotation 781S: between 49.0 and 55.0 at 20, calculated on the anhydrous, solvent-free basis.
Test solution: 10 mg per mL, in methanol.
Microbial enumeration tests 61 and Tests for specified microorganisms 62 The total aerobic microbial count does not exceed 100 cfu per g. It meets the requirements of the tests for the absence of Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella species, and Escherichia coli.
Bacterial endotoxins 85 It contains not more than 0.4 USP Endotoxin Unit per mg of paclitaxel.
Water, Method Ic 921: not more than 4.0%.
Residue on ignition 281: not more than 0.2%.
Related compounds—
test 1 (for material labeled as isolated from natural sources)— If the material complies with this test, the labeling indicates that it meets USP Related compounds Test 1.
Diluent— Prepare as directed in the Assay.
Solution A— Prepare filtered and degassed acetonitrile.
Solution B— Prepare filtered and degassed water.
Mobile phase— Use variable mixtures of Solution A and Solution B as directed for Chromatographic system. Make adjustments if necessary (see System Suitability under Chromatography 621).
System suitability solution— Dissolve accurately weighed quantities of USP Paclitaxel Related Compound A RS and USP Paclitaxel Related Compound B RS in methanol to obtain a solution having known concentrations of about 10 µg of each per mL. Transfer 5.0 mL of this solution to a 50-mL volumetric flask, dilute with Diluent to volume, and mix.
Standard solution— Dissolve, with the aid of sonication, an accurately weighed quantity of USP Paclitaxel RS in Diluent, and dilute quantitatively, and stepwise if necessary, with Diluent to obtain a solution having a known concentration of about 5 µg per mL.
Test solution— Use the Assay preparation.
Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 227-nm detector and a 4.6-mm × 25-cm column that contains 5-µm packing L43. The flow rate is about 2.6 mL per minute. The column temperature is maintained at 30. The chromatograph is programmed as follows.
Time
(minutes)
Solution A
(%)
Solution B
(%)
Elution
0–35 35 65 isocratic
35–60 35®80 65®20 linear gradient
60–70 80®35 20®65 linear gradient
70–80 35 65 isocratic
Chromatograph the System suitability solution, and record the peak responses as directed for Procedure: the relative retention times are about 0.78 for paclitaxel related compound A and 0.86 for paclitaxel related compound B (relative to the retention time for paclitaxel obtained from the Test solution); and the resolution, R, between paclitaxel related compound A and paclitaxel related compound B is not less than 1.0. Chromatograph the Standard solution, and record the peak responses as directed for Procedure: the relative standard deviation for replicate injections is not more than 2.0%.
Procedure— Inject a volume (about 15 µL) of the Test solution into the chromatograph, record the chromatogram, and measure the areas for the major peaks. Calculate the percentage of each impurity in the portion of Paclitaxel taken by the formula:
100(Fri / rU)
in which F is the relative response factor for each impurity peak (see Table 1 for values); ri is the peak area for each individual impurity; and rU is the peak area for paclitaxel.
Table 1
Relative
Retention
Time
Relative
Response
Factor (F)
Name Limit (%)
0.24 1.29 Baccatin III 0.2
0.53 1.00 10-Deacetylpaclitaxel 0.5
0.57 1.00 7-Xylosylpaclitaxel 0.2
0.78 1.26 Cephalomannine (paclitaxel related compound A) a11
0.78 1.26 2¢¢,3¢¢-Dihydrocephalomannine a21
0.86 1.00 10-Deacetyl-7-epipaclitaxel (paclitaxel related compound B) 0.5
1.10 1.00 Benzyl analog3 b12
1.10 1.00 3¢¢,4¢¢-Dehydropaclitaxel C b22
1.40 1.00 7-Epicephalomannine 0.3
1.85 1.00 7-Epipaclitaxel 0.5
1  Resolution may be incomplete for these peaks, depending upon the relative amounts present; the sum of a1 and a2 is not more than 0.5%.
2  Resolution may be incomplete for these peaks, depending upon the relative amounts present; the sum of b1 and b2 is not more than 0.5%.
3  The following chemical name is assigned to the related compound, benzyl analog:Baccatin III 13-ester with (2R,3S)-2-hydroxy-3-phenyl-3-(2-phenylacetylamino)propanoic acid.
In addition to not exceeding the limits for paclitaxel related impurities in Table 1, not more than 0.1% of any other single impurity is found; and not more than 2.0% of total impurities is found.
test 2 (for material labeled as produced by a semisynthetic process)— If the material complies with this test, the labeling indicates that it meets USP Related compounds Test 2.
Diluent— Use acetonitrile.
Solution A— Use a filtered and degassed mixture of water and acetonitrile (3:2).
Solution B— Use filtered and degassed acetonitrile.
Mobile phase— Use variable mixtures of Solution A and Solution B as directed for Chromatographic system. Make adjustments if necessary (see System Suitability under Chromatography 621).
System suitability solution— Dissolve accurately weighed quantities of USP Paclitaxel RS and USP Paclitaxel Related Compound B RS in Diluent, shaking and sonicating if necessary, to obtain a solution having known concentrations of about 0.96 mg and 0.008 mg per mL, respectively.
Test solution— Transfer about 10 mg of Paclitaxel, accurately weighed, to a 10-mL volumetric flask, dissolve in and dilute with Diluent to volume, shaking and sonicating if necessary, and mix.
Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 227-nm detector and a 4.6-mm × 15-cm column that contains 3-µm packing L1. The flow rate is about 1.2 mL per minute. The column temperature is maintained at 35. The chromatograph is programmed as follows.
Time
(minutes)
Solution A
(%)
Solution B
(%)
Elution
0–20 100 0 isocratic
20–60 100®10 0®90 linear gradient
60–62 10®100 90®0 linear gradient
62–70 100 0 isocratic
Chromatograph the System suitability solution, and record the peak responses as directed for Procedure: the relative retention times are about 0.94 for paclitaxel related compound B and 1.0 for paclitaxel; the resolution, R, between paclitaxel related compound B and paclitaxel is not less than 1.2; and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure— Separately inject equal volumes (about 15 µL) of the Diluent and the Test solution into the chromatograph, record the chromatograms, and measure the areas for all the peaks. Disregard any peaks due to the Diluent. Calculate the percentage of each impurity in the portion of Paclitaxel taken by the formula:
100(Fri / rs)
in which F is the relative response factor for each impurity (see Table 2 for values); ri is the peak area for each impurity obtained from the Test solution; and rs is the sum of the areas of all the peaks obtained from the Test solution.
Table 2
Relative
Retention
Time
Relative
Response
Factor (F)
Name Limit
(%)
0.11 1.24 10-Deacetylbaccatin III 0.1
0.20 1.29 Baccatin III 0.2
0.42 1.39 Photodegradant2 0.1
0.47 1.00 10-Deacetylpaclitaxel 0.5
0.80 1.00 2-Debenzoylpaclitaxel-2-
pentenoate
0.7
0.921 1.00 Oxetane ring opened, acetyl and benzoyl migrated2 x1
0.921 1.00 10-Acetoacetylpaclitaxel x2
0.941 1.00 10-Deacetyl-7-epipaclitaxel (paclitaxel related compound B) x3
1.37 1.00 7-Epipaclitaxel 0.4
1.45 1.00 10,13-Bissidechainpaclitaxel2 0.5
1.54 1.00 7-Acetylpaclitaxel 0.6
1.80 1.75 13-Tes-baccatin III 0.1
2.14 1.00 7-Tes-paclitaxel 0.3
1  Resolution may be incomplete for these peaks, depending upon the relative amounts present; the sum of x1, x2, and x3 is not more than 0.4%.
2  The following chemical names are assigned to the related compounds Photodegradant; Oxetane ring opened, acetyl and benzoyl migrated; and 10,13-Bissidechainpaclitaxel:
Photodegradant
(1R,2R,4S,5S,7R,10S,11R,12S,13S,15S,16S)-2,10-diacetyloxy-5,13-dihydroxy-4,16,17,17-tetramethyl-8-oxa-3-oxo-12-phenylcarbonyloxypentacyclo[11.3.1.01,11.04,11.07,10]heptadec-15-yl
(2R,3S)-2-hydroxy-3-phenyl-3-(phenylcarbonylamino)propanoate
Oxetane ring opened, acetyl and benzoyl migrated
(1S,2S,3R,4S,5S,7S,8S,10R,13S)-5,10-diacetyloxy-1,2,4,7-tetrahydroxy-8,12,15,15-tetramethyl-9-oxo-4-(phenylcarbonyloxymethyl)tricyclo[9.3.1.03,8]pentadec-11-en-13-yl
(2R,3S)-2-hydroxy-3-phenyl-3-(phenylcarbonylamino)propanoate
10,13-Bissidechainpaclitaxel
Baccatin III 13-ester with (2R,3S)-2-hydroxy-3-phenyl-3-(phenylcarbonylamino)propanoic acid, 10-ester with (2S,3S)-2-hydroxy-3-phenyl-3-(phenylcarbonylamino)propanoic acid
In addition to not exceeding the limits for paclitaxel related impurities in Table 2, not more than 0.1% of any other single impurity is found; and not more than 2.0% of total impurities is found.
test 3 (for material labeled as produced by a plant cell fermentation process)— If the material complies with this test, the labeling indicates that it meets USP Related compounds Test 3.
Solution A— Prepare a filtered and degassed mixture of water and acetonitrile (3:2).
Solution B— Prepare filtered and degassed acetonitrile.
Mobile phase— Use variable mixtures of Solution A and Solution B as directed for Chromatographic system. Make adjustments if necessary (see System Suitability under Chromatography 621).
System suitability solution— Dissolve USP Paclitaxel Impurity Mixture RS in acetonitrile, sonicating if necessary, to obtain a solution having a known concentration of about 1 mg per mL.
Standard solution— Dissolve an accurately weighed quantity of USP Paclitaxel RS in acetonitrile, sonicating if necessary, to obtain a solution having a known concentration of about 1 mg per mL.
Test solution— Transfer about 10 mg of Paclitaxel, accurately weighed, to a 10-mL volumetric flask. Dissolve in and dilute with acetonitrile to volume, sonicating if necessary, and mix.
Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 227-nm detector and a 4.6-mm × 15-cm column that contains 3-µm packing L1. The flow rate is about 1.2 mL per minute. The chromatograph is programmed as follows.
Time
(minutes)
Solution A
(%)
Solution B
(%)
Elution
0–28 100 0 isocratic
28–33 100®98 0®2 linear gradient
33–58 98®10 2®90 linear gradient
58–60 10 90 isocratic
60–63 10®100 90®0 linear gradient
63–70 100 0 isocratic
Chromatograph the System suitability solution, and record the peak responses as directed for Procedure: the resolution, R, between paclitaxel and benzyl analog is not less than 1.8. Chromatograph the Standard solution, and record the peak responses as directed for Procedure: the relative standard deviation for replicate injections is not more than 2.0%. [note—For the purpose of peak identification, the approximate relative retention times are given in Table 3. The relative retention times are measured versus Paclitaxel. ]
Table 3
Name Relative
Retention
Time
Limit
(%)
Propyl analog1 0.54 0.2
Cephalomannine
(Paclitaxel related
compound A)
0.76 0.5
sec-Butyl analog2 0.81 0.2
n-Butyl analog3 0.89 0.1
Benzyl analog 1.10 0.4
Baccatin VI 1.23 0.2
Pentyl analog4 1.31 0.2
7-Epipaclitaxel 1.51 0.4
1  The following chemical name is assigned to the related compound Propyl analog:Baccatin III 13-ester with (2R,3S)-3-butanoylamino-2-hydroxy-3-phenylpropanoic acid.
2  The following chemical name is assigned to the related compound sec-Butyl analog:Baccatin III 13-ester with (2R,3S)-2-hydroxy-3-(2-methylbutanoylamino)-3-phenylpropanoic acid.
3  The following chemical name is assigned to the related compound n-Butyl analog:Baccatin III 13-ester with (2S,3S)-2-hydroxy-3-(pentanoylamino)-3-phenylpropanoic acid.
4  The following chemical name is assigned to the related compound Pentyl analog:Baccatin III 13-ester with (2R,3S)-3-(hexanoylamino)-2-hydroxy-3-phenylpropanoic acid.
Procedure— Inject a volume (about 12 µL) of the Test solution into the chromatograph, record the chromatogram, and measure the areas for all the peaks. Calculate the percentage of each impurity in the portion of Paclitaxel taken by the formula:
100(ri / rU)
in which ri is the response of each individual impurity; and rU is the sum of the areas of all the peaks obtained from the Test solution. In addition to not exceeding the limits for paclitaxel related impurities in Table 3, not more than 0.1% of any other single impurity is found; and not more than 2.0% of total impurities is found.
Assay—
Diluent— Prepare a mixture of methanol and acetic acid (200:1).
Mobile phase— Prepare a filtered and degassed mixture of water and acetonitrile (11:9). Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard preparation— Dissolve, using sonication if necessary, an accurately weighed quantity of USP Paclitaxel RS in Diluent, and dilute quantitatively, and stepwise if necessary, with Diluent to obtain a solution having a known concentration of about 1 mg per mL.
Assay preparation— Transfer about 10 mg of Paclitaxel, accurately weighed, to a 10-mL volumetric flask. Dissolve in Diluent, using sonication if necessary, dilute with Diluent to volume, and mix.
Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 227-nm detector and a 4.6-mm × 25-cm column that contains 5-µm packing L43. The flow rate is about 1.5 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the tailing factor is between 0.7 and 1.3; and the relative standard deviation for replicate injections is not more than 1.5%.
Procedure— Separately inject equal volumes (about 10 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the areas for the major peaks. Calculate the quantity, in mg, of C47H51NO14 in the portion of Paclitaxel taken by the formula:
10C(rU / rS)
in which C is the concentration, in mg per mL, of USP Paclitaxel RS in the Standard preparation; and rU and rS are the peak responses for paclitaxel obtained from the Assay preparation and the Standard preparation, respectively.
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