Paclitaxel

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

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C₄₇H₅₁NO₁₄ 853.92

Benzenepropanoic acid, β-(benzoylamino)-α-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-[2aα, 4β,4aβ,6β,9α(αR*,βS*),11α,12α,12aα,12bα]];

(2aR,4S,4aS,6R,9S,115,125, 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; (2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-9-{[(2R,3S)-3-Benzamido-2-hydroxy-3-phenylpropanoyl]oxy}-12-(benzoyloxy)-4,11-dihydroxy-4a,8,13,13-tetramethyl-5-oxo-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-b]oxete-6,12b(2aH)-diyl diacetate CAS RN^®: 33069-62-4; UNII: P88XT4IS4D.

1 DEFINITION

Paclitaxel contains NLT 97.0% and NMT 102.0% of paclitaxel (C₄₇H₅₁NO₁₄), calculated on the anhydrous and solvent-free basis.

[CAUTION-Paclitaxel is cytotoxic. Great care should be taken to prevent inhaling particles of Paclitaxel and exposing the skin to it.]

2 IDENTIFICATION

A. SPECTROSCOPIC IDENTIFICATION TESTS (197), Infrared Spectroscopy: 197K

B. The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.

3 ASSAY

3.1 PROCEDURE

Diluent: Methanol and acetic acid (200:1)

Mobile phase: Acetonitrile and water (45:55)

Standard solution: 1 mg/mL of USP Paclitaxel RS in Diluent. Sonicate to dissolve if necessary.

Sample solution: 1 mg/mL of Paclitaxel in Diluent. Sonicate to dissolve if necessary.

3.2 Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: LC

Detector: UV 227 nm

Column: 4.6-mm x 25-cm; 5-µm packing L43

Flow rate: 1.5 mL/min

Injection volume: 10 µL

3.3 System suitability

Sample: Standard solution

Suitability requirements

Tailing factor: 0.7-1.3

Relative standard deviation: NMT 1.5%

3.4 Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of paclitaxel (C₄₇H₅₁NO₁₄) in the portion of Paclitaxel taken:

Result = (r_U/r_S) x (C_S/C_U) x 100

r_U = peak response of paclitaxel from the Sample solution

r_S = peak response of paclitaxel from the Standard solution

C_S = concentration of USP Paclitaxel RS in the Standard solution (mg/mL)

C_U = concentration of Paclitaxel in the Sample solution (mg/mL)

Acceptance criteria: 97.0%-102.0%, on the anhydrous and solvent-free basis

4 IMPURITIES

4.1 RESIDUE ON IGNITION (281)

NMT 0.2%

Change to read:

4.2 ORGANIC IMPURITIES

4.2.1 Test 1

(for material labeled as isolated from natural sources): If the material complies with this test, the labeling indicates that it meets the requirements of USP Organic Impurities Test 1.

Solution A: Acetonitrile

Solution B: Water

Mobile phase: See Table 1.

Table 1

Diluent: Methanol and acetic acid (200:1)

System suitability stock solution: 10 µg/mL each of USP Paclitaxel Related Compound A RS and USP Paclitaxel Related Compound B RS in methanol

System suitability solution: 1 µg/mL each of USP Paclitaxel Related Compound A RS and USP Paclitaxel Related Compound B RS from System suitability stock solution in Diluent

Standard solution: 5 µg/mL of USP Paclitaxel RS in Diluent. Sonicate to dissolve if necessary.

Sample solution: 1 mg/mL of Paclitaxel in Diluent. Sonicate to dissolve if necessary.

Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: LC

Detector: UV 227 nm

Column: 4.6-mm x 25-cm; 5-µm packing L43

Column temperature: 30°

Flow rate: 2.6 mL/min

Injection volume: 15 µL

System suitability

Samples: System suitability solution and Standard solution

[NOTE-See Table 2 for the relative retention times.]

Suitability requirements

Resolution: NLT 1.0 between paclitaxel related compound A and paclitaxel related compound B, System suitability solution

Relative standard deviation: NMT 2.0%, Standard solution

Analysis

Sample: Sample solution

Calculate the percentage of each specified and unspecified impurity in the portion of Paclitaxel taken:

Result = (r_U/r_S) x 1/F x 100

r_U = peak response of each individual impurity

r_S = peak response of paclitaxel

F = relative response factor for each individual impurity (see Table 2)

Acceptance criteria: See Table 2.

Table 2

^a (2aR,4S, 4aS,6R,9S,11S,12S,12aR,12bS)-12-(Benzoyloxy)-4,9,11-trihydroxy-4a,8,13,13-tetramethyl-5-oxo-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca[3,4] benzo[1,2-b]oxete-6,12b(2aH)-diyl diacetate.

^b (2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-12b-Acetoxy-9-{[(2R,3S)-3-benzamido-2-hydroxy-3-phenylpropanoyl]oxy}-4,6,11-trihydroxy-4a,8,13,13-tetramethyl-5-oxo-2a,3,4,4a,5,6,9,10,11,12,12a,12b-dodecahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-b]oxet-12-yl benzoate.

^c (2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-9-{[(2R,3S)-3-Benzamido-2-hydroxy-3-phenylpropanoyl]oxy}-12-(benzoyloxy)-11-hydroxy-4a,8,13,13-tetramethyl-5-oxo-4-(D-xylopyranosyloxy)-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca [3,4]benzo[1,2-b]oxete-6,12b(2aH)-diyl diacetate.

^d Resolution may be incomplete for these peaks depending upon the relative amounts present; the sum of a₁ and a₂ is NMT 0.5%.

^e 2",3"-Dihydrocephalomannine;(2aR,4S, 4aS,6R,9S,11S,12S,12aR,12bS)-12-(Benzoyloxy)-4,11-dihydroxy-9-{[(2R,3S)-2-hydroxy-3-(2-methylbutanamido)-3-phenylpropanoyl]oxy}-4a,8,13,13-tetramethyl-5-oxo-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca [3,4]benzo[1,2-b]oxete-6,12b(2aH)-diyl diacetate.

^f (2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-12-(Benzoyloxy)-4,11-dihydroxy-9-{[(2R,3S)-2-hydroxy-3-phenyl-3-(2-phenylacetamido)propanoyl]oxy}-4a,8,13,13-tetramethyl-5-oxo-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca [3,4]benzo[1,2-b]oxete-6,12b(2aH)-diyl diacetate.

^g Resolution may be incomplete for these peaks depending upon the relative amounts present; the sum of b₁ and b₂ is NMT 0.5%.

^h (2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-12-(Benzoyloxy)-9-({(2R,3S)-3-[(Z)-hex-3-enamido]-2-hydroxy-3-phenylpropanoyl}oxy)-4,11-dihydroxy-4a,8,13,13-tetramethyl-5-oxo-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-b]oxete-6,12b(2aH)-diyl diacetate.

ⁱ (2aR,4R,4aS,6R,9S,11S,12S,12aR,12bS)-12-(Benzoyloxy)-4,11-dihydroxy-9-({(2R,3S)-2-hydroxy-3-[(E)-2-methylbut-2-enamido]-3-phenylpropanoyl}oxy)-4a,8,13,13-tetramethyl-5-oxo-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-b]oxete-6,12b(2aH)-diyl diacetate.

^j (2aR,4R,4aS,6R,9S,11S,12S,12aR,12bS)-9-{[(2R,3S)-3-Benzamido-2-hydroxy-3-phenylpropanoyl]oxy}-12-(benzoyloxy)-4,11-dihydroxy-4a,8,13,13-tetramethyl-5-oxo-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-b]oxete-6,12b(2aH)-diyl diacetate.

4.2.2 Test 2

(for material labeled as produced by a semisynthetic process): If the material complies with this test, the labeling indicates that it meets the requirements of USP Organic Impurities Test 2.

Solution A: Acetonitrile and water (40:60)

Solution B: Acetonitrile

Mobile phase: See Table 3.

Table 3

System suitability solution: 0.96 mg/mL of USP Paclitaxel RS and 0.008 mg/mL of USP Paclitaxel Related Compound B RS in Solution B. Sonicate to dissolve if necessary.

Sample solution: 1 mg/mL of Paclitaxel in Solution B. Sonicate to dissolve if necessary.

Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: LC

Detector: UV 227 nm

Column: 4.6-mm x 15-cm; 3-µm packing L1

Column temperature: 35°

Flow rate: 1.2 mL/min

Injection volume: 15 µL

System suitability

Sample: System suitability solution

[NOTE-See Table 4 for the relative retention times.]

Suitability requirements

Resolution: NLT 1.2 between paclitaxel related compound B and paclitaxel

Relative standard deviation: NMT 2.0% for paclitaxel

Analysis

Sample: Sample solution

Calculate the percentage of each specified and unspecified impurity in the portion of Paclitaxel taken:

Result = (r_U/r_T) x 1/F x 100

r_U = peak response of each individual impurity from the Sample solution

r_T = sum of all the peak responses from the Sample solution

F = relative response factor for each impurity (see Table 4)

Acceptance criteria: See Table 4.

Table 4

^a (2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-12b-(Acetyloxy)-12-(benzoyloxy)-1,2a,3,4,4a,6,9,10,11,12,12a,12b-dodecahydro-4,6,9,11-tetrahydroxy-4a,8,13,13-tetramethyl-7,11-methano-5H-cyclodeca[3,4]benz[1,2-b]oxet-5-one.(ERR 1-Oct-2024)

^b (2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-12-(Benzoyloxy)-4,9,11-trihydroxy-4a,8,13,13-tetramethyl-5-oxo-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca[3,4] benzo[1,2-b]oxete-6,12b(2aH)-diyl diacetate.

^c (1S,2S,4S,5S,5aR,6R,7aS,8S,9aR,11aS,11bS)-4-{[(2R,3S)-3-Benzamido-2-hydroxy-3-phenylpropanoyl]oxy}-1-(benzoyloxy)-2,8-dihydroxy-5,7a,12,12-tetramethyl-7-oxodecahydro-1H-2,5a-methanocyclohepta[3,3a]indeno[5,4-b]oxete-6,11a(11H)-diyl diacetate.

^d (2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-12b-Acetoxy-9-{[(2R,3S)-3-benzamido-2-hydroxy-3-phenylpropanoyl]oxy}-4,6,11-trihydroxy-4a,8,13,13-tetramethyl-5-oxo-2a,3,4,4a,5,6,9,10,11,12,12a,12b-dodecahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-b]oxet-12-yl benzoate.

^e (2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-9-{[(2R,3S)-3-Benzamido-2-hydroxy-3-phenylpropanoyl]oxy}-4,11-dihydroxy-4a,8,13,13-tetramethyl-12-{[(E)-2-methylbut-2-enoyl]oxy}-5-oxo-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-b]oxete-6,12b(2aH)-diyl diacetate.

^f (1S,3S,4S,4aR,5S,6S,8S,11R,12aS)-8-{[(2R,3S)-3-Benzamido-2-hydroxy-3-phenylpropanoyl] oxy}-4-[(benzoyloxy)methyl]-1,4,5,6-tetrahydroxy-9,12a,13,13-tetramethyl-12-oxo-1,2,3,4,4a,5,6,7,8,11,12,12a-dodecahydro-6,10-methanobenzocyclodecen-3,11-diyl diacetate.

^g Resolution may be incomplete for these peaks depending upon the relative amounts present; the sum of x₁, x₂, and x₃ is NMT 0.4%.

^h (2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-6-Acetoxy-9-{[(2R,3S)-3-benzamido-2-hydroxy-3-phenylpropanoyl]oxy}-4,11-dihydroxy-4a,8,13,13-tetramethyl-5-oxo-12b-[(3-oxobutanoyl)oxy]-2a,3,4,4a,5,6,9,10,11,12,12a,12b-dodecahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-bloxet-12-yl benzoate.

ⁱ (2aR, 4R,4aS,6R,9S,11S,12S,12aR,12bS)-9-{[(2R,3S)-3-Benzamido-2-hydroxy-3-phenylpropanoyl]oxy}-12-(benzoyloxy)-4,11-dihydroxy-4a,8,13,13-tetramethyl-5-oxo-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-b]oxete-6,12b(2aH)-diyl diacetate.

^j (2aR,4S, 4aS,6S,9S,11S,12S,12aR,12bS)-12b-Acetoxy-12-(benzoyloxy)-4,11-dihydroxy-4a,8,13,13-tetramethyl-5-oxo-2a,3,4,4a,5,6,9,10,11,12,12a,12b-dodecahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-b]oxete-6,9-diyl (2R,2'R,3S,3'S)-bis(3-benzamido-2-hydroxy-3-phenylpropanoate).

^k (2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-9-{[(2R,3S)-3-Benzamido-2-hydroxy-3-phenylpropanoyl]oxy}-12-(benzoyloxy)-11-hydroxy-4a,8,13,13-tetramethyl-5-oxo-4-(acetyloxy)-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-b]oxete-6,12b(2aH)-diyl diacetate.

^l 13-Tes-baccatin III; (2aR,4S, 4aS,6R,9S,11S,12S,12aR,12bS)-6,12b-(Diacetyloxy)-12-(benzoyloxy)-9-(triethylsilyloxy)-1,2a,3,4,4a,6,9,10,11,12,12a,12b-dodecahydro-4,11-dihydroxy-4a,8,13,13-tetramethyl-7,11-methano-5H-cyclodeca[3,4]benz[1,2-b]oxet-5-one.

^m 7-Tes-paclitaxel; (2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-9-{[(2R,3S)-3-Benzamido-2-hydroxy-3-phenylpropanoyl]oxy}-12-(benzoyloxy)-4-(triethylsilyloxy)-11-hydroxy-4a,8,13,13-tetramethyl-5-oxo-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-b]oxete-6,12b(2aH)-diyl diacetate.

4.2.3 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 the requirements of USP Organic Impurities Test 3.

Solution A: Acetonitrile and water (40:60)

Solution B: Acetonitrile

Mobile phase: See Table 5.

Table 5

System suitability solution: 1 mg/mL of USP Paclitaxel Impurity Mixture RS in Solution B. Sonicate to dissolve if necessary.

Standard solution: 1 mg/mL of USP Paclitaxel RS in Solution B. Sonicate to dissolve if necessary.

Sample solution: 1 mg/mL of Paclitaxel in Solution B. Sonicate to dissolve if necessary.

Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: LC

Detector: UV 227 nm

Column: 4.6-mm x 15-cm; 3-µm packing L1

Flow rate: 1.2 mL/min

Injection volume: 12 µL

System suitability

Samples: System suitability solution and Standard solution

[NOTE-See Table 6 for the relative retention times.]

Suitability requirements

Resolution: NLT 1.8 between paclitaxel and paclitaxel benzyl analog, System suitability solution

Relative standard deviation: NMT 2.0%, Standard solution

Analysis

Sample: Sample solution

Calculate the percentage of each specified and unspecified impurity in the portion of Paclitaxel taken:

Result = (r_U/r_T) x 100

r_U = peak response of each individual impurity from the Sample solution

r_T = sum of all the peak responses from the Sample solution

Acceptance criteria: See Table 6.

Table 6

^a (2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-12-(Benzoyloxy)-9-{[(2R,3S)-3-butyramido-2-hydroxy-3-phenylpropanoyl)oxy}-4,11-dihydroxy-4a,8,13,13-tetramethyl-5-oxo-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-b]oxete-6,12b(2aH)-diyl diacetate.

^b 2",3"-Dihydrocephalomannine; (2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-12-(Benzoyloxy)-4,11-dihydroxy-9-{[(2R,3S)-2-hydroxy-3-(2-methylbutanamido)-3-phenylpropanoyl)oxy}-4a,8,13,13-tetramethyl-5-oxo-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-b]oxete-6,12b(2aH)-diyl diacetate.

^c (2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-12-(Benzoyloxy)-4,11-dihydroxy-9-{[(2R,3S)-2-hydroxy-3-pentanamido-3-phenylpropanoyl]oxy}-4a,8,13,13-tetramethyl-5-oxo-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-b]oxete-6,12b(2aH)-diyl diacetate.

^d (2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-12-(Benzoyloxy)-4,11-dihydroxy-9-{[(2R,3S)-2-hydroxy-3-phenyl-3-(2-phenylacetamido)propanoyl]oxy}-4a,8,13,13-tetramethyl-5-oxo-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-b]oxete-6,12b(2aH)-diyl diacetate.

^e (2aR,4S, 4aS,5R,6R,9S,11S,12S,12aR,12bS)-12-(Benzoyloxy)-11-hydroxy-4a,8,13,13-tetramethyl-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-b]oxete-4,5,6,9,12b(2aH)-pentayl pentaacetate.

^f (2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-12-(Benzoyloxy)-9-{[(2R,3S)-3-hexanamido-2-hydroxy-3-phenylpropanoyl]oxy}-4,11-dihydroxy-4a,8,13,13-tetramethyl-5-oxo-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-b]oxete-6,12b(2aH)-diyl diacetate.

^g (2aR,4R,4aS,6R,9S,11S,12S,12aR,12bS)-9-{[(2R,3S)-3-Benzamido-2-hydroxy-3-phenylpropanoyl]oxy}-12-(benzoyloxy)-4,11-dihydroxy-4a,8,13,13-tetramethyl-5-oxo-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-b]oxete-6,12b(2aH)-diyl diacetate.

5 SPECIFIC TESTS

5.1 MICROBIAL ENUMERATION TESTS (61) and TESTS FOR SPECIFIED MICROORGANISMS (62)

The total aerobic microbial count does not exceed 102 cfu/g. It meets the requirements of the tests for absence of Salmonella species, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa.

5.2 OPTICAL ROTATION (781S), Procedures, Specific Rotation

Sample solution: 10 mg/mL of paclitaxel in methanol

Acceptance criteria: -49.0° to 55.0° at 20°, calculated on the anhydrous, solvent-free basis

5.3 WATER DETERMINATION (921), Method I, Method Ic

NMT 4.0%

5.4 BACTERIAL ENDOTOXINS TEST (85)

Where the label states Paclitaxel must be subjected to further processing during the preparation of injectable dosage forms, the level of bacterial endotoxins are such that the requirement under the relevant dosage form monograph(s) in which Paclitaxel is used can be met.

6 ADDITIONAL REQUIREMENTS

6.1 PACKAGING AND STORAGE

Preserve in tight, light-resistant containers, and store at controlled room temperature.

6.2 LABELING

Label it to indicate the type of process used to produce the material and the Organic Impurities test with which the material complies. Where Paclitaxel is intended for use in preparing injectable or other sterile dosage forms, the label states that it is sterile or must be subjected to further processing during the preparation of injectable or other sterile dosage forms to ensure acceptable levels of bacterial endotoxins.

6.3 USP REFERENCE STANDARDS (11)

USP Paclitaxel RS

USP Paclitaxel Related Compound A RS

Cephalomannine; (2aR,4S,4aS,6R,9S,11S,12S,12aR,12bS)-12-(Benzoyloxy)-4,11-dihydroxy-9-({(2R,3S)-2-hydroxy-3-[(E)-2-methylbut-2-enamido]-3-phenylpropanoyl}oxy)-4a,8,13,13-tetramethyl-5-oxo-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca [3,4]benzo[1,2-bloxete-6,12b(2aH)-diyl diacetate.

C₄₅H₅₃NO₁₄ 831.91

USP Paclitaxel Related Compound B RS

10-Deacetyl-7-epipaclitaxel; (2aR,4R,4aS,6R,9S,11S,12S,12aR,12bS)-12b-Acetoxy-9-{[(2R,3S)-3-benzamido-2-hydroxy-3-phenylpropanoyl]oxy}-4,6,11-trihydroxy-4a,8,13,13-tetramethyl-5-oxo-2a,3,4,4a,5,6,9,10,11,12,12a,12b-dodecahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-b]oxet-12-yl benzoate.

C₄₅H₄₉NO₁₃ 811.88

USP Paclitaxel Impurity Mixture RS

It contains a mixture of the following two compounds:

Paclitaxel;

Paclitaxel benzyl analog: (2aR,4S,4aS, 6R,9S,11S,12S,12aR,12bS)-12-(Benzoyloxy)-4,11-dihydroxy-9-{[(2R,3S)-2-hydroxy-3-phenyl-3-(2-phenylacetamido)propanoyl]oxy}-4a,8,13,13-tetramethyl-5-oxo-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H-7,11-methanocyclodeca[3,4]benzo[1,2-bloxete-6,12b(2aH)-diyl diacetate.

C₄₈H₅₃NO₁₄ 867.95