Verapamil Hydrochloride Compounded Oral Solution

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

Verapamil Hydrochloride Compounded Oral Solution contains NLT 90.0% and NMT 110.0% of the labeled amount of verapamil hydrochloride (C₂₇H₃₈N₂O₄ · HCI).

Prepare Verapamil Hydrochloride Compounded Oral Solution 50 mg/mL as follows (see Pharmaceutical Compounding-Nonsterile Preparations (795)).

Add Verapamil Hydrochloride powder and about 40 mL of Vehicle to a mortar, and mix. Add the Vehicle in small portions almost to volume, and mix thoroughly after each addition. Transfer the contents of the mortar, stepwise and quantitatively, to a calibrated bottle. Add sufficient Vehicle to bring the preparation to final volume, and mix well.

2 ASSAY

PROCEDURE

Solution A: 0.01 N sodium acetate solution containing 33 mL/L of acetic acid

Mobile phase: Acetonitrile, 2-aminoheptane, and Solution A (50:0.5:50). Filter, and degas.

Standard solution: 500 µg/mL of USP Verapamil Hydrochloride RS in Mobile phase

Sample solution: Agitate containers of Oral Solution for 30 min on a rotating mixer, remove a 5-mL sample, and store in a clear glass vial at -70° until analyzed. At the time of analysis, remove the sample from the freezer, allow it to reach room temperature, and mix on a vortex mixer for 30 s. Pipet 1.0 mL of the sample into a 100-mL volumetric flask, and dilute with Mobile phase to volume. 

Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: LC

Detector: UV 278 nm

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

Flow rate: 0.5 mL/min

Injection volume: 20 µL

System suitability

Sample: Standard solution

[NOTE-The retention time for verapamil hydrochloride is about 4.8 min.]

Suitability requirements

Relative standard deviation: NMT 0.7% for replicate injections

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of verapamil hydrochloride (C₂₇H₃₈N₂O₄ · HCI) in the portion of Oral Solution taken: 

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

r_U = peak response from the Sample solution

r_S = peak response from the Standard solution

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

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

Acceptance criteria: 90.0%-110.0%

3 SPECIFIC TESTS

pH (791): 3.8-4.8

4 ADDITIONAL REQUIREMENTS

PACKAGING AND STORAGE: Package in tight, light-resistant containers. Store at controlled room temperature or in a refrigerator.

BEYOND-USE DATE: NMT 60 days after the date on which it was compounded when stored at controlled room temperature or in a refrigerator

LABELING: Label to indicate the Beyond-Use Date.

USP REFERENCE STANDARDS (11)

USP Verapamil Hydrochloride RS