Telmisartan

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

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

DOWNLOAD PDF HERE

1 DEFINITION

Telmisartan contains NLT 98.0% and NMT 102.0% (USP 1-May-2021) of telmisartan (C₃₃H₃₀N₄O₂), calculated on the dried basis.

2 IDENTIFICATION

Change to read:

A. Spectroscopic Identification Tests 〈197〉, Infrared Spectroscopy: 197K or 197A (USP 1-May-2021)

Analysis: If the spectra obtained shows differences, proceed with the samples prepared as follows. Separately dissolve a quantity of USP Telmisartan RS and the Telmisartan sample in alcohol. [Note—Heating the solution may be necessary for complete dissolution.] Cool the solution in an ice bath, filter the crystals, and dry at 105°.

Acceptance criteria: Meets the requirements

Change to read:

B. The retention time of the major peak from the Sample solution corresponds to that from the Standard solution, as obtained in the Assay. (USP 1-May-2021)

3 ASSAY

Change to read:

Procedure

[Note—Protect all solutions containing telmisartan from light.]

Solution A: 2.0 g/L of monobasic potassium phosphate and 3.8 g/L of sodium 1-pentanesulfonate in water. Adjust with 1 M phosphoric acid to a pH of 3.0.

Solution B: Acetonitrile and methanol (80:20)

Mobile phase: See Table 1.

Table 1

Standard stock solution A: 5 mg/mL of USP Telmisartan RS prepared as follows. Transfer a suitable amount of USP Telmisartan RS to a suitable volumetric flask. Add methanol to about 50% of the flask volume and 1 M sodium hydroxide to 1% of the flask volume. Sonicate to dissolve. Dilute with methanol to volume.

Standard stock solution B: 25 μg/mL of USP Telmisartan Related Compound B RS prepared as follows. Transfer a suitable amount of USP Telmisartan Related Compound B RS to a suitable volumetric flask. Add methanol to about 50% of the flask volume and 1 M sodium hydroxide to 1% of the flask volume. Sonicate to dissolve. Dilute with methanol to volume.

System suitability solution: 2.5 mg/mL of the USP Telmisartan RS and 2.5 μg/mL of USP Telmisartan Related Compound B RS in methanol, from Standard stock solution A and Standard stock solution B

Standard solution: 0.25 mg/mL USP Telmisartan RS in methanol, from Standard stock solution A

Sample stock solution: 2.5 mg/mL of Telmisartan prepared as follows. Transfer a suitable amount of Telmisartan to a suitable volumetric flask. Add methanol to about 50% of the flask volume and 1 M sodium hydroxide to 1% of the flask volume. Sonicate to dissolve. Dilute with methanol to volume.

Sample solution: 0.25 mg/mL of Telmisartan in methanol, from Sample stock solution

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 230 nm

Column: 4.0-mm × 12.5-cm; 5-μm packing L1

Column temperature: 40°

Flow rate: 1.0 mL/min

Injection volume: 2 μL

System suitability

Samples: System suitability solution and Standard solution

Suitability requirements

Resolution: NLT 3.0 between telmisartan and telmisartan related compound B, System suitability solution

Tailing factor: NMT 2.0, Standard solution

Relative standard deviation: NMT 0.73%, Standard solution

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of telmisartan in the portion of Telmisartan taken:

Result = (r_U/r_S) × (C_S/C_U) × 100

r_U = peak response of telmisartan from the Sample solution

r_S = peak response of telmisartan from the Standard solution

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

C_U = concentration of Telmisartan in the Sample solution (mg/mL) (USP 1-May-2021)

Acceptance criteria: 98.0%–102.0% (USP 1-May-2021) on the dried basis

4 IMPURITIES

Residue on Ignition 〈281〉

Sample: 1 g

Acceptance criteria: NMT 0.1%

Change to read:

Organic Impurities

[Note—Protect all solutions containing telmisartan from light. ]

Solution A, Solution B, Mobile phase, Standard stock solution A, Standard stock solution B, System suitability solution, Sample stock solution, and Chromatographic system: Proceed as directed in the Assay.

Sensitivity solution: 1.25 μg/mL USP Telmisartan RS in methanol, from Standard solution (USP 1-May-2021)

Standard solution: 25 μg/mL USP Telmisartan RS in methanol, from Standard stock solution A (USP 1-May-2021)

Sample solution: 2.5 mg/mL of Telmisartan. Use undiluted Sample stock solution. (USP 1-May-2021)

System suitability

Samples: System suitability solution, Sensitivity solution, (USP 1-May-2021) and Standard solution

[Note—See Table 2 for relative retention times.]

Suitability requirements

Resolution: NLT 3.0 between telmisartan and telmisartan related compound B, System suitability solution

Tailing factor: Between 0.9 and 1.5 for telmisartan related compound B, System suitability solution

Relative standard deviation: NMT 5.0% for the telmisartan peak, Standard solution

Signal-to-noise ratio: NLT 10, Sensitivity solution (USP 1-May-2021)

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of any individual specified and unspecified (USP 1-May-2021) impurity in the portion of Telmisartan taken:

Result = (r_U/r_S) × (C_S/C_U) × 100

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

r_S = peak response of telmisartan from the Standard solution

C_S = concentration of USP Telmisartan RS in the Standard solution (mg/mL) (USP 1-May-2021)

C_U = concentration of Telmisartan in the Sample solution (mg/mL) (USP 1-May-2021)

Acceptance criteria: See Table 2. The reporting threshold is 0.05%. (USP 1-May-2021)

Table 2

^a 1,7′-Dimethyl-2′-propyl-1H,3′H-2,5′-bibenzo[d]imidazole.

^b 1-[(2′-Carboxybiphenyl-4-yl)methyl]-4-methyl-2-propyl-1H-benzo[d]imidazole-6-carboxylic acid.

^c 4′-[(1,7′-Dimethyl-2′-propyl-1H,3′H-2,5′-bibenzo[d]imidazol-3′-yl)methyl]biphenyl-2-carboxamide.

^d tert-Butyl 4′-[(1,7′-dimethyl-2′-propyl-1H,3′H-2,5′-bibenzo[d]imidazol-3′-yl)methyl]biphenyl-2-carboxylate.

5 SPECIFIC TESTS

Loss on Drying 〈731〉

Sample: 1.0 g

Analysis: Dry the Sample at 105° to constant weight.

Acceptance criteria: NMT 1.5%

6 ADDITIONAL REQUIREMENTS

Change to read:

Packaging and Storage: Preserve in tight containers, and protect from light. Store at controlled room temperature. (USP 1-May-2021)

USP Reference Standards 〈11〉

USP Telmisartan RS

USP Telmisartan Related Compound B RS