Pioglitazone and Glimepiride 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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1 DEFINITION

Pioglitazone and Glimepiride Tablets contain an amount of pioglitazone hydrochloride (C₁₉H₂₀N₂O₃S·HCI) equivalent to NLT 90.0% and NMT 110.0% of the labeled amount of pioglitazone (C₁₉H₂₀N₂O₃S), and NLT 90.0% and NMT 110.0% of the labeled amount of glimepiride (C₂₄H₃₄N₄O₅S).

2 IDENTIFICATION

A. ULTRAVIOLET ABSORPTION

Sample: Transfer 1 Tablet to a suitable container, and add 0.1 N hydrochloric acid to obtain a final concentration of about 0.1 mg/mL of glimepiride. Shake until the Tablet disintegrates. Pass a 2-mL portion of the resulting suspension through a suitable filter of 0.45-µm pore size. Use the filtrate for the identification of pioglitazone, and use the filter for the identification of glimepiride.

Pioglitazone

Sample solution: Dilute a portion of the filtrate obtained in the Sample with 0.1 N hydrochloric acid to obtain a solution containing about 0.03 mg/mL of pioglitazone.

Acceptance criteria: The UV absorption spectrum exhibits a maximum between 267 and 271 nm.

Glimepiride

Sample solution: Wash the filter, as obtained in the Sample, with 100 mL of 0.1 N hydrochloric acid, and discard the filtrate. Wash the filter with 20 mL of methanol, and use the filtrate.

Acceptance criteria: The UV absorption spectrum exhibits a maximum between 227 and 231 nm.

B. The retention times of the pioglitazone and glimepiride peaks of the Sample solution correspond to those of the Standard solution, as obtained in the Assay.

3 ASSAY

3.1 PROCEDURE

Buffer: 6.9 g/L of monobasic sodium phosphate in water, adjusted with diluted phosphoric acid to a pH of 4.0

Mobile phase: Acetonitrile and Buffer (1:1)

Diluent: Acetonitrile and 0.1 N hydrochloric acid (9:1)

Standard stock solution: 0.66 mg/mL of USP Pioglitazone Hydrochloride RS and 0.08 mg/mL of USP Glimepiride RS in Diluent

Standard solution: 66 µg/mL of pioglitazone hydrochloride and 8 µg/mL of glimepiride in Mobile phase from the Standard stock solution

Resolution stock solution: Dilute 1.0 mL of ethyl benzoate with Mobile phase to 100 mL. Further dilute 1.0 mL of the resulting solution with Mobile phase to 100 mL.

System suitability solution: Transfer 5.0 mL of the Standard stock solution and 5.0 mL of the Resolution stock solution to a 50-mL volumetric flask, and dilute with Mobile phase to volume.

Sample stock solution: Transfer 20 Tablets to a suitable container. Add 200.0 mL of Diluent, and shake vigorously for at least 20 min. If disintegration is not complete, sonicate until the Tablets are completely disintegrated, and then shake for an additional 10 min. Pass through a suitable filter of 0.2-µm pore size, discarding the first few mL of filtrate. Further dilute 5.0 mL of the filtrate with Diluent to 50.0 mL.

Sample solution: Transfer 10.0 mL of the Sample stock solution to a 50-mL volumetric flask, and dilute with Mobile phase to volume to obtain a solution with the nominal concentrations listed in Table 1.

Table 1

3.2 Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: LC

Detector: UV 228 nm

Column: 4.6-mm x 5-cm; 3-µm packing L1

Column temperature: 25 ± 5°

Flow rate: 0.8 mL/min. [NOTE-The flow rate may be adjusted to achieve the retention time of the pioglitazone peak of about 2.3 min.]

Injection volume: 20 µL

3.3 System suitability

Samples: Standard solution and System suitability solution

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

Table 2

Suitability requirements

Resolution: NLT 4 between pioglitazone and ethyl benzoate; NLT 3 between ethyl benzoate and glimepiride, System suitability solution

Relative standard deviation: NMT 1.0% for the pioglitazone peak; NMT 1.0% for the glimepiride peak, Standard solution

3.4 Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of pioglitazone (C₁₉H₂₀N₂O₃S) in the portion of Tablets taken:

Result = (r_U/r_S) x (C_S/C_U) x (M_r1/M_r2) x 100

r_U = peak response of pioglitazone from the Sample solution

r_S = peak response of pioglitazone from the Standard solution

C_S = concentration of USP Pioglitazone Hydrochloride RS in the Standard solution (µg/mL)

C_U = nominal concentration of pioglitazone in the Sample solution (µg/mL)

M_r1 = molecular weight of pioglitazone, 356.44

M_r2 = molecular weight of pioglitazone hydrochloride, 392.90

Calculate the percentage of the labeled amount of glimepiride (C₂₄H₃₄N₄O₅S) in the portion of Tablets taken:

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

r_U = peak response of glimepiride from the Sample solution

r_S = peak response of glimepiride from the Standard solution

C_S = concentration of USP Glimepiride RS in the Standard solution (µg/mL)

C_U = nominal concentration of glimepiride in the Sample solution (µg/mL)

Acceptance criteria: 90.0%-110.0% for each of the labeled amounts of pioglitazone and glimepiride

4 PERFORMANCE TESTS

4.1 DISSOLUTION (711)

4.1.1 Test 1

Pioglitazone

Medium: Hydrochloric acid buffer pH 2.0 (see Reagents, Indicators, and Solutions-Buffer Solutions); 900 mL

Apparatus 2: 75 rpm

Time: 15 min

Mobile phase and Chromatographic system: Proceed as directed in the Assay.

Standard stock solution: 0.37 mg/mL of USP Pioglitazone Hydrochloride RS dissolved first in methanol using 20% of the final volume, and then diluted with Medium to volume

Standard solution: Transfer 10.0 mL of the Standard stock solution to a 100-mL volumetric flask, and dilute with Medium to volume.

Sample solution: Pass a portion of the solution under test through a suitable filter of 0.45-µm pore size.

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 pioglitazone (C₁₉H₂₀N₂O₃S) dissolved:

Result = (r_U/r_S) x (C_S/L) x V x (M_r1/M_r2) x 100

r_U = peak response of pioglitazone from the Sample solution

r_S = peak response of pioglitazone from the Standard solution

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

L = labeled amount of pioglitazone (mg/Tablet)

V = volume of Medium, 900 mL

M_r1 = molecular weight of pioglitazone, 356.44

M_r2 = molecular weight of pioglitazone hydrochloride, 392.90

Tolerances: NLT 80% (Q) of the labeled amount of pioglitazone (C₁₉H₂₀N₂O₃S) is dissolved.

Glimepiride

Medium: pH 6.8 sodium phosphate buffer containing 0.2% of sodium dodecyl sulfate (6.9 g/L of monobasic sodium phosphate, 0.896 g/L of sodium hydroxide, and 2 g/L of sodium dodecyl sulfate in water, adjusted with 1 N sodium hydroxide to a pH of 6.8); 900 mL

Apparatus 2: 75 rpm

Time: 15 min

Mobile phase and Chromatographic system: Proceed as directed in the Assay. The flow rate may be adjusted to achieve the retention time of the glimepiride peak of about 5.4 min.

Standard stock solution: 0.22 mg/mL of USP Glimepiride RS in acetonitrile

Standard solution: L/900 mg/mL of USP Glimepiride RS in Medium, where L is the labeled amount of glimepiride, in mg/Tablet, 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.

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 glimepiride (C₂₄H₃₄N₄O₅S) dissolved:

Result = (r_U/r_S) x (C_S/L) x V x 100

r_U = peak response of glimepiride from the Sample solution

r_S = peak response of glimepiride from the Standard solution

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

L = labeled amount of glimepiride (mg/Tablet)

V = volume of Medium, 900 mL

Tolerances: NLT 80% (Q) of the labeled amount of glimepiride (C₂₄H₃₄N₄O₅S) is dissolved.

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

Pioglitazone

Medium: Hydrochloric acid buffer pH 2.0 (see Reagents, Indicators, and Solutions-Buffer Solutions); 900 mL, deaerated

Apparatus 2: 75 rpm

Time: 30 min

Buffer: 0.02 M sodium phosphate buffer pH 2.5 (2.75 g/L of monobasic sodium phosphate in water, adjusted with phosphoric acid to a pH of 2.5)

Solution A: Acetonitrile and Buffer (28:72)

Solution B: Acetonitrile and Buffer (70:30)

Mobile phase: See Table 3.

Table 3

Return to original conditions and re-equilibrate the system.

Standard stock solution: 0.2 mg/mL of USP Pioglitazone Hydrochloride RS dissolved first in alcohol using 20% of the final volume, and then diluted with Medium to volume

Standard solution: Transfer 5.0 mL of the Standard stock solution to a 25-mL volumetric flask, and dilute with Medium to volume.

Sample solution: Pass a portion of the solution under test through a suitable filter of 0.45-µm pore size.

Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: LC

Detector: UV 225 nm for pioglitazone (0-4.0 min) and UV 230 nm for glimepiride (4.0-7.0 min)

Column: 4.6-mm x 15-cm; 3.5-µm packing L1

Column temperature: 30°

Flow rate: 1.5 mL/min

Injection volume: 20 µL

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 pioglitazone (C₁₉H₂₀N₂O₃S) dissolved:

Result = (r_U/r_S) x (C_S/L) x V x (M_r1/M_r2) × 100

r_U = peak response of pioglitazone from the Sample solution

r_S = peak response of pioglitazone from the Standard solution

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

L = labeled amount of pioglitazone (mg/Tablet)

V = volume of Medium, 900 mL

M_r1 = molecular weight of pioglitazone, 356.44

M_r2 = molecular weight of pioglitazone hydrochloride, 392.90

Tolerances: NLT 80% (Q) of the labeled amount of pioglitazone (C₁₉H₂₀N₂O₃S) is dissolved.

Glimepiride

Medium: pH 6.8 sodium phosphate buffer containing 0.2% of sodium dodecyl sulfate (6.9 g/L of monobasic sodium phosphate, 0.896 g/L of sodium hydroxide, and 2 g/L of sodium dodecyl sulfate in water, adjusted with 1 N sodium hydroxide to a pH of 6.8); 900 mL

Apparatus 2: 75 rpm

Time: 15 min

Mobile phase and Chromatographic system: Proceed as directed in Dissolution Test 2, Pioglitazone.

Standard stock solution: 0.2 mg/mL of USP Glimepiride RS in alcohol

Standard solution: L/900 mg/mL of USP Glimepiride RS in Medium, where L is the labeled amount of glimepiride, in mg/Tablet, from the Standard stock solution

suitable f Sample solution: Pass a portion of the solution under test through a suitable filter of 0.45-µm pore size.

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 glimepiride (C₂₄H₃₄N₄O₅S) dissolved:

Result = (r_U/r_S) x (C_S/L) x V x 100

r_U = peak response of glimepiride from the Sample solution

r_S = peak response of glimepiride from the Standard solution

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

L = labeled amount of glimepiride (mg/Tablet)

V = volume of Medium, 900 mL

Tolerances: NLT 80% (Q) of the labeled amount of glimepiride (C₂₄H₃₄N₄O₅S) is dissolved.

4.2 UNIFORMITY OF DOSAGE UNITS (905)

Meet the requirements for Content Uniformity for pioglitazone and glimepiride

5 IMPURITIES

5.1 ORGANIC IMPURITIES: PIOGLITAZONE

Mobile phase: Acetonitrile, 0.1 M ammonium acetate, and glacial acetic acid (25:25:1)

Diluent: Acetonitrile and 0.1 N hydrochloric acid (9:1)

Standard stock solution: 0.2 mg/mL of USP Pioglitazone Hydrochloride RS in Diluent

Standard solution: 2 µg/mL of USP Pioglitazone Hydrochloride RS in Mobile phase from the Standard stock solution

Resolution stock solution: Dilute 1.0 mL of ethyl benzoate to 100.0 mL with acetonitrile. Further dilute 1.0 mL of the resulting solution with acetonitrile to 100.0 mL.

System suitability solution: Transfer 2.0 mL of the Resolution stock solution into a 100-mL volumetric flask. Add 1.0 mL of the Standard stock solution, and dilute with Mobile phase to volume.

Sample stock solution: Transfer 10 Tablets to an appropriate volumetric flask such that the nominal glimepiride concentration is 0.4 mg/mL. Add Diluent to approximately 80% of the total volume. Shake vigorously for at least 20 min, and dilute with Diluent to volume. Pass through a suitable filter of 0.2-um pore size, discarding the first few mL of filtrate.

Sample solution: Transfer a suitable volume of the Sample stock solution to a 25-mL volumetric flask, and dilute with Mobile phase to volume to obtain a solution containing 240 µg/mL of pioglitazone.

Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: LC

Detector: UV 269 nm

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

Column temperature: 25 ± 5°

Flow rate: 0.8 mL/min. [NOTE-The flow rate may be adjusted to achieve the retention time of the pioglitazone peak of about 7 min.]

Injection volume: 40 µL

Run time: At least 4 times the retention time of the pioglitazone peak

System suitability

Samples: Standard solution and System suitability solution [NOTE-Elution order is the pioglitazone peak followed by ethyl benzoate.]

Suitability requirements

Resolution: NLT 10 between pioglitazone and ethyl benzoate, System suitability solution

Tailing factor: NMT 1.5 for the pioglitazone peak, System suitability solution

Relative standard deviation: NMT 5.0%, Standard solution

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of each pioglitazone related impurity in the portion of Tablets taken:

Result = (r_U/r_S) x (C_S/C_U) x (M_r1/M_r2) x 100

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

r_S = peak response of pioglitazone from the Standard solution

C_S = concentration of USP Pioglitazone Hydrochloride RS in the Standard solution (µg/mL)

C_U = nominal concentration of pioglitazone in the Sample solution (µg/mL)

M_r1 = molecular weight of pioglitazone, 356.44

M_r2 = molecular weight of pioglitazone hydrochloride, 392.90

Acceptance criteria

Any individual pioglitazone related impurity: NMT 0.2%

Total pioglitazone related impurities: NMT 0.6%

[NOTE-Disregard the peak due to glimepiride, which elutes at about 16.5 min.]

Change to read:

5.2 ORGANIC IMPURITIES: GLIMEPIRIDE

Buffer: 0.007 M sodium phosphate, pH 1.6 (0.97 g/L of monobasic sodium phosphate in water, adjusted with dilute phosphoric acid to a pH of 1.6)

Diluent: Acetonitrile and 0.1 N hydrochloric acid (9:1)

Solution A: Acetonitrile and Buffer (52:48)

Solution B: Acetonitrile and Buffer (70:30)

Mobile phase: See Table 4 (ERR 1-Oct-2018).

Table 4 (ERR 1-Oct-2018)

Standard stock solution: 0.2 mg/mL of USP Glimepiride RS in Diluent

Standard solution: 2 µg/mL of USP Glimepiride RS in Solution A from the Standard stock solution

Resolution stock solution: Dilute 1.0 mL of ethyl benzoate with acetonitrile to 100.0 mL. Further dilute 1.0 mL of the resulting solution with acetonitrile to 100.0 mL.

System suitability solution: Transfer 2 mL of the Resolution stock solution into a 100-mL volumetric flask, add 1.0 mL of the Standard stock solution, and dilute with Solution A to volume.

Sample stock solution: Transfer 10 Tablets to an appropriate volumetric flask such that the nominal glimepiride concentration is 0.4 mg/mL. Add Diluent to approximately 80% of the total volume. Shake vigorously for at least 20 min, and dilute with Diluent to volume. Pass through a suitable filter of 0.2-µm pore size, discarding the first few mL of filtrate.

Sample solution: Equivalent to 0.2 mg/mL glimepiride in Solution A from the Sample stock solution

Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: LC

Detector: UV 228 nm

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

Column temperature: 25 ± 5°

Flow rate: 1.0 mL/min. [NOTE-The flow rate may be adjusted to achieve the retention time of the glimepiride peak of about 25 min.)

Injection volume: 40 µL

System suitability

Samples: Standard solution and System suitability solution

[NOTE-Elution order is ethyl benzoate followed by glimepiride.]

Suitability requirements

Resolution: NLT 10 between ethyl benzoate and glimepiride, System suitability solution

Tailing factor: NMT 1.5 for glimepiride, System suitability solution

Relative standard deviation: NMT 5.0%, Standard solution

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of each glimepiride related impurity in the portion of Tablets taken:

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

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

r_S = peak response of glimepiride from the Standard solution

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

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

F = relative response factor for each impurity (see Table 5 (ERR 1-Oct-2018))

Acceptance criteria: See Table 5 (ERR 1-Oct-2018) [NOTE-Disregard the peaks due to inactive ingredients and to pioglitazone that elute before the glimepiride sulfonamide peak.]

Table 5 (ERR 1-Oct-2018)

^a [p-[2-(3-Ethyl-4-methyl-2-oxo-3-pyrroline-1-carboxamido)ethyl]phenyl] sulfonamide.

6 ADDITIONAL REQUIREMENTS

6.1 PACKAGING AND STORAGE

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

6.2 LABELING

When more than one dissolution test is given, the labeling states the Dissolution Test used only if Test 1 is not used.

6.3 USP REFERENCE STANDARDS (11)

USP Glimepiride RS

USP Pioglitazone Hydrochloride RS