Quinapril 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

Quinapril Tablets contain quinapril hydrochloride (C₂₅H₃₀N₂O₅ . HCl) equivalent to NLT 90.0% and NMT 110.0% of the labeled amount of quinapril (C₂₅H₃₀N₂O₅).

2 IDENTIFICATION

Change to read:

A. The UV spectrum of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay. (USP 1-May-2021)

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

Change to read:

3.1 Procedure

Diluent: Acetonitrile and water (35:65)

(USP 1-May-2021)

Mobile phase: Acetonitrile, methanesulfonic acid, and water (35:0.2:65)

(USP 1-May-2021)

Standard solution: 0.108 mg/mL of USP Quinapril Hydrochloride RS, equivalent to 0.1 mg/mL of quinapril, in Diluent (USP 1-May-2021)

Sample solution: Nominally 0.1 mg/mL of quinapril in Diluent prepared as follows. Transfer a suitable amount of Tablets to a suitable

volumetric flask. (USP 1-May-2021) Add about 60% of the flask volume of Diluent, and sonicate until the Tablets have disintegrated. Shake by

mechanical means for about 15 min and dilute with Diluent to volume. Pass through a suitable filter, discarding the first portion of the filtrate.

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 214 nm. For Identification A, use a diode array detector in the range of 190–400 nm. (USP 1-May-2021)

Column: 6.0-mm × 4-cm; 3-µm packing L10

Flow rate: 1.2 mL/min

Injection volume: 20 µL

System suitability

Sample: Standard solution

Suitability requirements

(USP 1-May-2021)

Tailing factor: NMT 1.5

Relative standard deviation: NMT 2.0%

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of quinapril (C₂₅H₃₀N₂O₅) in the portion of Tablets taken:

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

r_U = peak response of quinapril from the Sample solution

r_S = peak response of quinapril from the Standard solution

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

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

M_r1 = molecular weight of quinapril, 438.52

M_r2 = molecular weight of quinapril hydrochloride, 474.98

Acceptance criteria: 90.0%–110.0%

4 PERFORMANCE TESTS

Change to read:

4.1 Dissolution 〈711〉

Medium: Water; 900 mL

Apparatus 1: 100 rpm

Time: 30 min

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

Standard solution: (L/900) mg/mL of quinapril, where L is the label claim in mg/Tablet, prepared as follows. (USP 1-May-2021) Dissolve a

suitable amount of USP Quinapril Hydrochloride RS in methanol. Make any necessary volumetric adjustments with water.

Sample solution: Pass a portion of the solution under test through a suitable filter.

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of quinapril (C₂₅H₃₀N₂O₅) dissolved:

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

r_U = peak response of quinapril from the Sample solution

r_S = peak response of quinapril from the Standard solution

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

L = label claim (mg/Tablet)

V = volume of Medium, 900 mL

M_r1 = molecular weight of quinapril, 438.52

M_r2 = molecular weight of quinapril hydrochloride, 474.98  (USP 1-May-2021)

Tolerances: NLT 80% (Q) of the labeled amount of quinapril (C₂₅H₃₀N₂O₅) is dissolved.

Change to read:

4.2 Uniformity of Dosage Units 〈905〉: Meet the requirements

(USP 1-May-2021)

5 IMPURITIES

Change to read:

5.1 Organic Impurities

Diluent, 

(USP 1-May-2021) Mobile phase, Sample solution, and Chromatographic system: Proceed as directed in the Assay.

System suitability solution: 0.1 mg/mL of USP Quinapril Hydrochloride RS and 0.005 mg/mL each of USP Quinapril Related Compound A RS and USP Quinapril Related Compound B RS in Diluent

Sensitivity solution: 0.1 µg/mL of USP Quinapril Hydrochloride RS in Diluent (USP 1-May-2021)

Standard solution: 0.5 µg/mL each of USP Quinapril Hydrochloride RS, USP Quinapril Related Compound A RS, and USP Quinapril Related

Compound B RS in Diluent

System suitability

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

Suitability requirements

Resolution: NLT 2.0 between quinapril and quinapril related compound A; NLT 2.0 between quinapril and quinapril related compound B,

System suitability solution

(USP 1-May-2021)

Tailing factor: NMT 1.5 for the quinapril and quinapril related compound A peaks; NMT 2.0 for the quinapril related compound B peak,

Standard solution

Relative standard deviation: NMT 2.0% for quinapril; NMT 3.0% for each quinapril related compound, Standard solution

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

Analysis

Samples: Sample solution and Standard solution

Calculate the percentage of quinapril related compound A or quinapril related compound B in the portion of Tablets taken:

Result = (r_U/r_S) × (C_S/C_U) × 100

r_U = peak response of quinapril related compound A or quinapril related compound B from the Sample solution

r_S = peak response of quinapril related compound A or quinapril related compound B from the Standard solution

C_S = concentration of USP Quinapril Related Compound A RS or USP Quinapril Related Compound B RS in the Standard solution (mg/mL)

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

Calculate the percentage of any unspecified degradation product in the portion of Tablets taken:

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

r_U = peak response of any unspecified degradation product from the Sample solution

r_S = peak response of quinapril from the Standard solution

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

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

M_r1 = molecular weight of quinapril, 438.52

M_r2 = molecular weight of quinapril hydrochloride, 474.98  (USP 1-May-2021)

Acceptance criteria: See Table 1. The reporting threshold is 0.1%. (USP 1-May-2021)

Table 1

6 ADDITIONAL REQUIREMENTS

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

Change to read:

USP Reference Standards 〈11〉

USP Quinapril Hydrochloride RS

USP Quinapril Related Compound A RS

Ethyl (S)-2-((3S,11aS)-3-methyl-1,4-dioxo-1,3,4,6,11,11a-hexahydro-2H-pyrazino[1,2-b]isoquinolin-2-yl)-4-phenylbutanoate.

C₂₅H₂₈N₂O₄ 420.51 (USP 1-May-2021)

USP Quinapril Related Compound B RS

(S)-2-{[(S)-1-Carboxy-3-phenylpropyl]-L-alanyl}-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid. (USP 1-May-2021)

C₂₃H₂₆N₂O₅ 410.47