Olmesartan Medoxomil Tablets

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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To view the Notice from the Expert Committee that posted in conjunction with this accelerated revision, please click https://www.uspnf.com/rb-olmesartan-medoxomil-tabs-20250131. 

1 DEFINITION 

Olmesartan Medoxomil Tablets contain NLT 90.0% and NMT 110.0% of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆).

2 IDENTIFICATION 

A. The UV absorption spectra of the major peak of the Sample solution exhibit maxima and minima at the same wavelengths as those of the corresponding peak of the Standard solution, as obtained in the Assay. 

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 

Procedure 

Solution A: 3.1 g/L of formic acid 

Solution B: Acetonitrile and Solution A (10:90) Solution C: Acetonitrile and Solution A (90:10) Mobile phase: See Table 1. 

Table 1 

Diluent: Acetonitrile and water (60:40) 

Standard solution: 40 µg/mL of USP Olmesartan Medoxomil RS in Diluent 

Sample stock solution: Prepare solutions of nominal concentrations of olmesartan medoxomil in Diluent as follows. To NLT 10 Tablets for 5- and 20-mg Tablet strengths and NLT 5 Tablets for 40-mg Tablet strength in a 200-mL volumetric flask, add Diluent to volume. Sonicate with occasional shaking to disintegrate the Tablets completely, centrifuge the suspension, and use the supernatant. Sample solution: Nominally 40 µg/mL of olmesartan medoxomil in Diluent from Sample stock solution 

Chromatographic system 

(See Chromatography 〈621〉, System Suitability.) 

Mode: LC 

Detector: UV 249 nm. For Identification A, use a diode array detector in the range of 200–400 nm. 

Column: 2.1-mm × 5-cm; 1.7-µm packing L1 

Column temperature: 35° 

Flow rate: 0.6 mL/min 

Injection volume: 1 µL 

System suitability 

Sample: Standard solution 

Suitability requirements 

Tailing factor: NMT 2.0 

Relative standard deviation: NMT 1.0% 

Analysis 

Samples: Standard solution and Sample solution 

Calculate the percentage of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆) in the portion of Tablets taken:  

Result = (r_U/r_S) × (C_S/C_U) × 100 

r_U = peak response of olmesartan medoxomil from the Sample solution 

r_S = peak response of olmesartan medoxomil from the Standard solution 

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

C_U = nominal concentration of olmesartan medoxomil in the Sample solution (mg/mL) 

Acceptance criteria: 90.0%–110.0% 

4 PERFORMANCE TESTS 

Change to read: 

Dissolution 〈711〉 

Test 1 

Medium: pH 6.8 phosphate buffer (see Reagents, Indicators, and Solutions—Buffer Solutions)  

For Tablets labeled to contain 5 mg: 500 mL 

For Tablets labeled to contain 20 and 40 mg: 1000 mL 

Apparatus 2: 50 rpm 

Time: 30 min 

Diluent: Acetonitrile and water (60:40) 

Standard stock solution: 2 mg/mL of USP Olmesartan Medoxomil RS in Diluent 

Standard solution: (L/V) mg/mL of USP Olmesartan Medoxomil RS in Medium, where L is the label claim in mg/Tablet and V is the volume of the Medium in mL from the Standard stock solution 

Sample solution: Pass a portion of the solution under test through a glass fiber filter  of 1.2-µm pore size. 

Instrumental conditions 

(See Ultraviolet-Visible Spectroscopy 〈857〉.) 

Mode: UV 

Analytical wavelength: 258 nm 

Cells 

For Tablets labeled to contain 5 and 20 mg: 1 cm 

For Tablets labeled to contain 40 mg: 0.5 cm 

Blank: Medium 

Analysis 

Samples: Standard solution and Sample solution 

Calculate the percentage of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆) dissolved: 

Result = (A_U/A_S) × C_S × V × (1/L) × 100 

A_U = absorbance of the Sample solution 

A_S = absorbance of the Standard solution 

C_S = concentration of the Standard solution (mg/mL) 

D= dilution factor of the Sample solution  

V = volume of Medium, 900 mL 

L = label claim (mg/Tablet) 

Tolerances: NLT 75% (Q) of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆) is dissolved. 

Test 2: If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 2. 

Medium: pH 7.2 phosphate buffer (see Reagents, Indicators, and Solutions—Buffer Solutions); 900 mL 

Apparatus 2: 75 rpm 

Time: 30 min 

Standard stock solution: 0.2 mg/mL of USP Olmesartan Medoxomil RS prepared as follows. Transfer an appropriate amount of USP Olmesartan Medoxomil RS into a suitable volumetric flask. Dissolve in 30% of the flask volume of acetonitrile. Dilute with Medium to volume and mix. 

Standard solution: (L/1000) mg/mL of USP Olmesartan Medoxomil RS in Medium, from the Standard stock solution, where L is the label claim in mg/Tablet 

Sample solution: Pass a portion of the solution under test through a suitable filter  of 0.45-µm pore size and discard the first few milliliters of the filtrate. 

Instrumental conditions 

Mode: UV 

Analytical wavelength: 257 nm 

Cell: 1 cm 

Blank: Medium 

Analysis 

Samples: Standard solution and Sample solution 

Calculate the percentage of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆) dissolved: 

Result = (A_U/A_S) × C_S × V × (1/L) × 100 

A_U = absorbance of the Sample solution 

A_S = absorbance of the Standard solution 

C_S = concentration of the Standard solution (mg/mL) 

D= dilution factor of the Sample solution  

V = volume of Medium, 900 mL 

L = label claim (mg/Tablet) 

Tolerances: NLT 80% (Q) of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆) is dissolved. 

Test 3: If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 3. 

Medium: 0.05 M hydrochloric acid; 900 mL 

Apparatus 2: 50 rpm 

Time: 45 min 

Buffer: 1.36 g/L of monobasic potassium phosphate in water. Adjust with phosphoric acid to a pH of 2.5. 

Solution A: Acetonitrile and Buffer (20:80) 

Solution B: Acetonitrile and Buffer (80:20) 

Mobile phase: See Table 2. 

Table 2 

Diluent A: Acetonitrile, water, and phosphoric acid (50:50:2) 

Diluent B: Medium and Diluent A (50:50) 

Standard stock solution: 0.22 mg/mL of USP Olmesartan Medoxomil RS in Diluent A, prepared as follows. Transfer an appropriate amount of USP Olmesartan Medoxomil RS to a suitable volumetric flask. Add Diluent A to 60% of the total volume and sonicate to dissolve. Dilute with Diluent A to volume and mix well. 

Standard solution 

For Tablets labeled to contain 5 mg: 2.75 μg/mL of USP Olmesartan Medoxomil RS in Diluent B from the Standard stock solution For Tablets labeled to contain 20 mg: 11 μg/mL of USP Olmesartan Medoxomil RS in Diluent B from the Standard stock solution For Tablets labeled to contain 40 mg: 22 μg/mL of USP Olmesartan Medoxomil RS in Diluent B from the Standard stock solution 

Sample solution: Pass a portion of the solution under test through a suitable filter  of 0.45-µm pore size and discard the first few milliliters of the filtrate. Transfer 5 mL of the filter ed test solution to a 10-mL volumetric flask and dilute with Diluent A to volume. Chromatographic system 

(See Chromatography 〈621〉, System Suitability.) 

Mode: LC 

Detector: UV 250 nm 

Column: 4.6-mm × 15-cm; 5-μm packing L7 

Temperatures 

Autosampler: 5° 

Column: 30° 

Flow rate: 1.5 mL/min 

Injection volume: 10 μL 

System suitability 

Sample: Standard solution 

[Note—The relative retention times for olmesartan and olmesartan medoxomil are 0.45 and 1.00, respectively.] 

Suitability requirements 

Tailing factor: NMT 2.0 for olmesartan medoxomil 

Relative standard deviation: NMT 2.0% for olmesartan medoxomil 

Analysis 

Samples: Standard solution and Sample solution 

Calculate the concentration (C₁) of olmesartan medoxomil (C₂₉H₃₀N₆O₆) in the Sample solution:  

Result = (r_U/r_S) × C_S 

r_U = peak response of olmesartan medoxomil from the Sample solution 

r_S = peak response of olmesartan medoxomil from the Standard solution 

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

Calculate the concentration (C₂) of olmesartan as olmesartan medoxomil (C₂₉H₃₀N₆O₆) in the Sample solution:  

Result = (r_U/r_S) × C_S × (1/F) ×  (M_r1/M_r2) 

r_U = peak response of olmesartan from the Sample solution 

r_S = peak response of olmesartan medoxomil from the Standard solution 

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

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

F = relative response factor, 0.88

M_r1 = molecular weight of olmesartan medoxomil, 558.59 

M_r2 = molecular weight of olmesartan, 446.50 

Calculate the percentage of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆) dissolved: 

Result = [(C₁+ C₂) × D] × V × (1/L) × 100  

C₁ = concentration of olmesartan medoxomil in the Sample solution (mg/mL) 

C₂ = concentration of olmesartan as olmesartan medoxomil in the Sample solution (mg/mL) 

D = dilution factor for the Sample solution 

V = volume of Medium, 900 mL 

L = label claim for olmesartan medoxomil (mg/Tablet) 

Tolerances: NLT 75% (Q) of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆) is dissolved. 

Test 4: If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 4. 

Medium: 0.1 M hydrochloric acid; 900 mL 

Apparatus 2: 50 rpm 

Time: 15 min 

Buffer: Dissolve 2.04 g of monobasic potassium phosphate in 1000 mL of water. Adjust with phosphoric acid to a pH of 3.0. Mobile phase: Acetonitrile and Buffer (40:60) 

Diluent: Acetonitrile and water (60:40) 

Standard stock solution: 1.1 mg/mL of USP Olmesartan Medoxomil RS in Diluent 

Standard solution 

[Note—Preserve immediately at 2°–8° after preparation.] 

For Tablets labeled to contain 5 mg: 5.5 μg/mL of USP Olmesartan Medoxomil RS in Medium from the Standard stock solution For Tablets labeled to contain 20 mg: 22 μg/mL of USP Olmesartan Medoxomil RS in Medium from the Standard stock solution For Tablets labeled to contain 40 mg: 44 μg/mL of USP Olmesartan Medoxomil RS in Medium from the Standard stock solution 

Sample solution: Pass a portion of the solution under test through a suitable filter  of 0.45-µm pore size and discard the first 1 mL of the filtrate. [Note—Preserve immediately at 2°–8° after preparation.] 

Chromatographic system 

(See Chromatography 〈621〉, System Suitability.) 

Mode: LC 

Detector: UV 250 nm 

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

Temperatures 

Autosampler: 8° 

Column: 40° 

Flow rate: 1.5 mL/min 

Injection volume: 10 μL 

System suitability 

Sample: Standard solution 

[Note—The relative retention times for olmesartan and olmesartan medoxomil are 0.24 and 1.00, respectively.] Suitability requirements 

Tailing factor: 0.8–1.5 for olmesartan medoxomil 

Relative standard deviation: NMT 2.0% for the sum of the peak responses of olmesartan and olmesartan medoxomil Analysis 

Samples: Standard solution and Sample solution 

Calculate the percentage of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆) dissolved: 

Result = (r_U/r_S) × C_S × V × (1/L) × 100 

r_U = sum of the peak responses of olmesartan and olmesartan medoxomil from the Sample solution 

r_S = sum of the peak responses of olmesartan and olmesartan medoxomil from the Standard solution 

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

V = volume of Medium, 900 mL 

L = label claim of olmesartan medoxomil (mg/Tablet) 

Tolerances: NLT 80% (Q) of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆) is dissolved. 

Test 5: If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 5. 

Medium: pH 6.8 phosphate buffer (Dissolve 68.0 g of monobasic potassium phosphate in 8000 mL of water in a suitable container. Adjust with diluted sodium hydroxide to a pH of 6.8 ± 0.05. Dilute with water to 10,000 mL); 900 mL. [Note—Tight control of the pH is critical.] Apparatus 2: 50 rpm. Use apex vessels. 

Time: 30 min 

Buffer: Dissolve 6.8 g of monobasic potassium phosphate in 1000 mL of water. Add 5 mL of triethylamine and mix. Adjust with phosphoric acid to a pH of 2.5. 

Mobile phase: Acetonitrile and Buffer (50:50) 

Diluent: Acetonitrile and Medium (50:50) 

Standard stock solution: 0.222 mg/mL of USP Olmesartan Medoxomil RS in Diluent . Sonication may be needed to dissolve. Standard solution 

[Note—Preserve at 2°–8° after preparation.] 

For Tablets labeled to contain 5 mg: 0.0027 mg/mL of USP Olmesartan Medoxomil RS in Diluent from the Standard stock solution For Tablets labeled to contain 20 mg: 0.0111 mg/mL of USP Olmesartan Medoxomil RS in Diluent from the Standard stock solution For Tablets labeled to contain 40 mg: 0.0222 mg/mL of USP Olmesartan Medoxomil RS in Diluent from the Standard stock solution 

Sample solution: Pass a portion of the solution under test through a suitable filter  of 0.45-µm pore size and discard the first 2 mL of the filtrate. Transfer 5.0 mL of the solution into a 10-mL volumetric flask. Dilute with acetonitrile to volume. [Note—Preserve at 2°–8° after preparation.] 

Chromatographic system 

(See Chromatography 〈621〉, System Suitability.) 

Mode: LC 

Detector: UV 250 nm 

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

Temperatures 

Autosampler: 5° 

Column: 40° 

Flow rate: 1.0 mL/min 

Injection volume: 20 μL 

Run time: NLT 2 times the retention time of olmesartan medoxomil 

System suitability 

Sample: Standard solution 

Suitability requirements 

Tailing factor: NMT 2.0 

Relative standard deviation: NMT 2.0% 

Analysis 

Samples: Standard solution and Sample solution 

Calculate the percentage of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆) dissolved: 

Result = (r_U/r_S) × C × D × V × (1/L) × 100 

r_U = peak response of olmesartan medoxomil from the Sample solution 

r_S = peak response of olmesartan medoxomil from the Standard solution 

C = concentration of USP Olmesartan Medoxomil RS in the Standard solution (mg/mL) 

D = dilution factor of the Sample solution 

V = volume of Medium, 900 mL 

L = label claim of olmesartan medoxomil (mg/Tablet) 

Tolerances: NLT 80% (Q) of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆) is dissolved. 

Test 6: If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 6. 

Medium: 0.05 M pH 6.8 phosphate buffer (dissolve 68 g of monobasic potassium phosphate and 9 g of sodium hydroxide in 10,000 mL of water; adjust with diluted sodium hydroxide solution or diluted phosphoric acid to a pH of 6.8); 900 mL 

Apparatus 2: 50 rpm 

Time: 30 min 

Buffer: Dissolve 6.8 g of monobasic potassium phosphate in 1000 mL of water. Adjust with diluted phosphoric acid to a pH of 3.0. Mobile phase: Acetonitrile and Buffer (40:60) 

Diluent: Acetonitrile and water (50:50) 

Standard stock solution A: 0.55 mg/mL of USP Olmesartan Medoxomil RS in Diluent . Sonication may be needed to dissolve. For Tablets labeled to contain 5 mg 

Standard stock solution B: 5.5 μg/mL of USP Olmesartan Medoxomil RS in Medium from Standard stock solution A Standard solution: 2.75 μg/mL of USP Olmesartan Medoxomil RS in Mobile phase from Standard stock solution B 

For Tablets labeled to contain 20 mg 

Standard stock solution C: 22 μg/mL of USP Olmesartan Medoxomil RS in Medium from Standard stock solution A Standard solution: 11 μg/mL of USP Olmesartan Medoxomil RS in Mobile phase from Standard stock solution C 

For Tablets labeled to contain 40 mg 

Standard stock solution D: 44 μg/mL of USP Olmesartan Medoxomil RS in Medium from Standard stock solution A Standard solution: 22 μg/mL of USP Olmesartan Medoxomil RS in Mobile phase from the Standard stock solution D Sample solution: Pass a portion of the solution under test through a suitable filter  of 0.45-µm pore size. Transfer 5.0 mL of the filtrate into a 10-mL volumetric flask. Dilute with Mobile phase to volume. Pass a portion of the solution through a suitable filter  of 0.45-µm pore size. [Note—The Sample solution is stable for 25 h at 5°.] 

Chromatographic system 

(See Chromatography 〈621〉, System Suitability.) 

Mode: LC 

Detector: UV 250 nm 

Column: 4.6-mm × 15-cm; 5-μm packing L1 

Temperatures 

Autosampler: 5° 

Column: 30° 

Flow rate: 2.0 mL/min 

Injection volume: 100 μL  

Run time: NLT 1.5 times the retention time of olmesartan medoxomil 

System suitability 

Sample: Standard solution 

Suitability requirements 

Tailing factor: NMT 2.0 

Relative standard deviation: NMT 2.0% 

Analysis 

Samples: Standard solution and Sample solution 

Calculate the percentage of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆) dissolved: 

Result = (r_U/r_S) × C_S × D × V × (1/L) × 100 

r_U = peak response of olmesartan medoxomil from the Sample solution 

r_S = peak response of olmesartan medoxomil from the Standard solution  

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

D = dilution factor for the Sample solution 

V = volume of Medium, 900 mL 

L = label claim of olmesartan medoxomil (mg/Tablet) 

Tolerances: NLT 70% (Q) of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆) is dissolved. 

Test 7: If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 7. Medium: 0.1 N hydrochloric acid; 900 mL 

Apparatus 2: 50 rpm 

Time: 20 min 

Diluent: Acetonitrile and water (60:40) 

Standard stock solution: 1.12 mg/mL of USP Olmesartan Medoxomil RS in Diluent 

Standard solution 

For Tablets labeled to contain 5 mg: 5.6 μg/mL of USP Olmesartan Medoxomil RS in Medium from the Standard stock solution For Tablets labeled to contain 20 mg or 40 mg: 11.2 μg/mL of USP Olmesartan Medoxomil RS in Medium from the Standard stock solution 

Sample solution: Pass a portion of the solution under test through a suitable filter  of 0.45-µm pore size and discard at least the first 5 mL of the filtrate. Dilute with Medium to a concentration that is similar to the Standard solution if necessary. 

Instrumental conditions 

(See Ultraviolet-Visible Spectroscopy 〈857〉.) 

Mode: UV 

Analytical wavelength: 257 nm 

Cell: 1 cm 

Blank: Medium 

Analysis 

Samples: Standard solution and Sample solution 

Calculate the percentage of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆) dissolved: 

Result = (A_U/A_S) × C_S × V × (1/L) × 100 

A_U = absorbance of the Sample solution 

A_S = absorbance of the Standard solution 

C_S = concentration of the Standard solution (mg/mL) 

D= dilution factor of the Sample solution  

V = volume of Medium, 900 mL 

L = label claim (mg/Tablet)

Tolerances: NLT 80% (Q) of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆) is dissolved. 

Test 8: If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 8. 

Medium: 0.05 M pH 6.8 phosphate buffer (dissolve 6.8 g of monobasic potassium phosphate and 0.9 g of sodium hydroxide in 1000 mL of water; adjust with 0.2 M sodium hydroxide solution or 0.2 M hydrochloric acid solution to a pH of 6.8); 900 mL 

Apparatus 2: 50 rpm 

Times 

For Tablets labeled to contain 5 mg and 20 mg: 30 min 

For Tablets labeled to contain 40 mg: 45 min 

Mobile phase: Acetonitrile and 0.2% phosphoric acid TS (35:65) 

Standard stock solution: 0.55 mg/mL of USP Olmesartan Medoxomil RS prepared as follows. Transfer a suitable amount of USP Olmesartan Medoxomil RS to a suitable volumetric flask. Dissolve in 60% of the flask volume of acetonitrile. Sonicate to dissolve if necessary. Dilute with Medium to volume. 

Standard solution 

For Tablets labeled to contain 5 mg: 2.8 µg/mL of USP Olmesartan Medoxomil RS prepared as follows. Dilute 2 mL of the Standard stock solution with Medium to 200 mL. Pass through a suitable filter  of 0.45-µm pore size. Further dilute 5 mL of this solution with Mobile phase to 10 mL, and mix well. 

For Tablets labeled to contain 20 mg: 11 µg/mL of USP Olmesartan Medoxomil RS prepared as follows. Dilute 4 mL of the Standard stock solution with Medium to 100 mL. Pass through a suitable filter  of 0.45-µm pore size. Further dilute 5 mL of this solution with Mobile phase to 10 mL, and mix well. 

For Tablets labeled to contain 40 mg: 22 µg/mL of USP Olmesartan Medoxomil RS prepared as follows. Dilute 4 mL of the Standard stock solution with Medium to 50 mL. Pass through a suitable filter  of 0.45-µm pore size. Further dilute 5 mL of this solution with Mobile phase to 10 mL, and mix well. 

Sample solution: Pass a portion of the solution under test through a suitable filter  of 0.45-µm pore size, and discard the first 3 mL of the filtrate. Immediately dilute 5 mL of the filtrate with Mobile phase to 10 mL, and mix well. 

Chromatographic system 

(See Chromatography 〈621〉, System Suitability.) 

Mode: LC 

Detector: UV 250 nm 

Column: 4.6-mm × 25-cm; 5-µm packing L1 

Temperatures 

Autosampler: 6° 

Column: 40° 

Flow rate: 1 mL/min 

Injection volume: 50 µL 

Run time: NLT 1.5 times the retention time of olmesartan medoxomil 

System suitability 

Sample: Standard solution 

Suitability requirements 

Tailing factor: NMT 2.0 

Relative standard deviation: NMT 2.0% 

Analysis 

Samples: Standard solution and Sample solution 

Calculate the percentage of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆) dissolved: 

Result = (r_U/r_S) × C_S × D × V × (1/L) × 100 

r_U = peak response of olmesartan medoxomil from the Sample solution 

r_S = peak response of olmesartan medoxomil from the Standard solution 

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

D = dilution factor of the Sample solution 

V = volume of Medium, 900 mL 

L = label claim of olmesartan medoxomil (mg/Tablet) 

Tolerances: NLT 75% (Q) of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆) is dissolved. 

Test 9: If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 9. 

Medium: 0.05 M phosphate buffer, pH 6.8 (dissolve 6.8 g of monobasic potassium phosphate in 1000 mL of water; adjust with 2.5 M sodium hydroxide solution to a pH of 6.8); 900 mL 

Apparatus 2: 75 rpm 

Time: 45 min 

Diluent: Acetonitrile and water (50:50) 

Standard stock solution A: 2.2 mg/mL of USP Olmesartan Medoxomil RS in Diluent. Sonicate to dissolve 

Standard stock solution B: 0.22 mg/mL of USP Olmesartan Medoxomil RS from Standard stock solution A in Medium Standard solution 

For Tablets labeled to contain 5 mg: 5.5 μg/mL of USP Olmesartan Medoxomil RS from Standard stock solution B in Medium For Tablets labeled to contain 20 mg or 40 mg: 11 μg/mL of USP Olmesartan Medoxomil RS from Standard stock solution B in Medium Sample solution: Pass a portion of the solution under test through a suitable filter  of 0.45-µm pore size, discarding an appropriate volume of filtrate so that a consistent result can be obtained. Dilute with Medium to a concentration that is similar to the Standard solution if necessary. 

Instrumental conditions 

(See Ultraviolet-Visible Spectroscopy 〈857〉.) 

Mode: UV 

Analytical wavelength: 256 nm 

Cell: 1 cm 

Blank: Medium 

Analysis 

Samples: Standard solution and Sample solution 

Calculate the percentage of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆) dissolved: 

Result = (A_U/A_S) × C_S × V × (1/L) × 100 

A_U = absorbance of the Sample solution 

A_S = absorbance of the Standard solution 

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

D= dilution factor of the Sample solution  

V = volume of Medium, 900 mL 

L = label claim (mg/Tablet) 

Tolerances: 

For Tablets labeled to contain 5 mg or 20 mg: NLT 80% (Q) of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆) is dissolved.  

For Tablets labeled to contain 40 mg: NLT 75% (Q) of the labeled amount of olmesartan medoxomil (C₂₉H₃₀N₆O₆) is dissolved.

Uniformity of Dosage Units 〈905〉: Meet the requirements 

5 IMPURITIES 

Organic Impurities 

Buffer: 0.015 M monobasic potassium phosphate. Adjust with phosphoric acid to a pH of 3.5. 

Solution A: Acetonitrile and Buffer (20:80) 

Solution B: Acetonitrile and Buffer (79:21) 

Mobile phase: See Table 3. 

Table 3 

Diluent: Acetonitrile and water (90:10) 

System suitability solution: 0.01 mg/mL each of USP Olmesartan Medoxomil RS and USP Olmesartan Medoxomil Related Compound A RS in Diluent 

Standard solution: 0.01 mg/mL of USP Olmesartan Medoxomil RS in Diluent 

Sensitivity solution: 0.002 mg/mL of USP Olmesartan Medoxomil RS in Diluent from the Standard solution 

Sample solution: Nominally 1 mg/mL of olmesartan medoxomil in Diluent prepared as follows. Dissolve a suitable number of Tablets in Diluent. Sonicate and/or shake occasionally to disintegrate the Tablets completely. Centrifuge and pass the supernatant through a suitable filter  of 0.45-µm pore size. 

Chromatographic system 

(See Chromatography 〈621〉, System Suitability.) 

Mode: LC 

Detector: UV 250 nm 

Column: 4.6-mm × 10-cm; 3.5-µm packing L7 

Column temperature: 40° 

Flow rate: 1 mL/min 

Injection volume: 10 µL 

System suitability 

Samples: System suitability solution and Sensitivity solution 

Suitability requirements 

Resolution: NLT 5 between olmesartan medoxomil and olmesartan medoxomil related compound A, System suitability solution Relative standard deviation: NMT 2.0% for both peaks, System suitability solution 

Signal-to-noise ratio: NLT 30, Sensitivity solution 

Analysis 

Samples: Standard solution and Sample solution 

Calculate the percentage of each degradation product in the portion of Tablets taken: 

Result = (r_U/r_S) × (C_S/C_U) × (1/F) × 100 

r_U = peak response of each degradation product from the Sample solution  

r_S = peak response of olmesartan medoxomil from the Standard solution 

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

C_U = nominal concentration of olmesartan medoxomil in the Sample solution (mg/mL) 

F = relative response factor (see Table 4) 

Acceptance criteria: See Table 4. Disregard peaks below 0.1%. 

Table 4 

^a 1-{[2′-(1H-Tetrazol-5-yl)biphenyl-4-yl]methyl}-4-(2-hydroxypropan-2-yl)-2-propyl-1H-imidazole-5-carboxylic acid. 

^b This is a process-related impurity that is controlled in the drug substance. 

^c 1-({2′-(1H-Tetrazol-5-yl)-[1,1′-biphenyl]-4-yl}methyl)-4-(2-{[1-({2′-(1H-tetrazol-5-yl)-[1,1′-biphenyl]-4-yl}methyl)-4-(2-hydroxypropan-2-yl)-2- propyl-1H-imidazole-5-carbonyl]oxy}propan-2-yl)-2-propyl-1H-imidazole-5-carboxylic acid. 

^d (5-Methyl-2-oxo-1,3-dioxol-4-yl)methyl 1-((2′-(1H-tetrazol-5-yl)biphenyl-4-yl)methyl)-4-(prop-1-en-2-yl)-2-propyl-1H-imidazole-5-carboxylate. 

6 ADDITIONAL REQUIREMENTS 

Packaging and Storage: Preserve in well-closed containers. Store at controlled room temperature. 

Labeling: When more than one Dissolution test is given, the labeling states the Dissolution test used only if Test 1 is not used. USP Reference Standards 〈11〉 

USP Olmesartan Medoxomil RS 

USP Olmesartan Medoxomil Related Compound A RS 

1-{[2′-(1H-Tetrazol-5-yl)biphenyl-4-yl]methyl}-4,4-dimethyl-2-propyl-1H-furo[3,4-d]imidazol-6(4H)-one. 

C₂₄H₂₄N₆O₂ 428.49