Griseofulvin Oral Suspension

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

Griseofulvin Oral Suspension contains NLT 90.0% and NMT 115.0% of the labeled amount of griseofulvin (C₁₇H₁₇ClO₆). It contains one or more suitable colors, diluents, avors, preservatives, and wetting agents.

2 IDENTIFICATION

A. 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

3.1 Procedure

Solution A: 100 mg/mL of sodium chloride in water

Mobile phase: Acetonitrile, tetrahydrofuran, and water (35:5:60). Degas for 5 min before use, and stir continuously during use.

Standard stock solution: 1.25 mg/mL of USP Griseofulvin RS in methanol

Standard solution: 0.125 mg/mL of USP Griseofulvin RS in Mobile phase from the Standard stock solution

Sample stock solution: Nominally 1.25 mg/mL of griseofulvin prepared as follows. Transfer a measured volume of Oral Suspension, freshly mixed and free from air bubbles and equivalent to 125 mg of griseofulvin, to a glass-stoppered, 50-mL centrifuge tube. Add 20 mL of methylene chloride and 20 mL of Solution A. Insert the stopper into the tube, and mix by rotating the tube for 10 min. Separate the phases by centrifugation, carefully remove the lower methylene chloride layer with a needle and syringe, and filter through methylene chloride-prerinsed anhydrous sodium sulfate into a 100-mL volumetric flask. Repeat the extraction with two additional 20-mL portions of methylene chloride, combining the extracts in the volumetric flask. Dilute with methylene chloride to volume.

Sample solution: Nominally 0.125 mg/mL of griseofulvin prepared as follows. Transfer 5.0 mL of Sample stock solution to a 50-mL volumetric flask, and evaporate on a steam bath under a stream of nitrogen to dryness. Transfer 4.0 mL of Mobile phase to the flask, swirl to dissolve the residue, and dilute with Mobile phase to volume.

3.2 Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 254 nm

Column: 4.6-mm × 25-cm; packing L10

Flow rate: 1 mL/min

Injection volume: 20 μL

3.3 System suitability

Sample: Standard solution

3.4 Suitability requirements

Relative standard deviation: NMT 2.0%

3.5 Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of griseofulvin (C₁₇H₁₇ClO₆) in the portion of Oral Suspension taken:

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

r_U = peak response from the Sample solution

r_S = peak response from the Standard solution

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

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

P = potency of griseofulvin in USP Griseofulvin RS (μg/mg)

F = conversion factor, 0.001 mg/μg

Acceptance criteria: 90.0%–115.0%

4 PERFORMANCE TESTS

Uniformity of Dosage Units 〈905〉: Meets the requirements for oral suspension packaged in single-unit containers

Deliverable Volume 〈698〉: Meets the requirements

5 SPECIFIC TESTS

pH 〈791〉: 5.5–7.5

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight containers.

Labeling: The label indicates that the griseofulvin contained is known as griseofulvin (microsize).

USP Reference Standards 〈11〉

USP Griseofulvin RS