Hyoscyamine Sulfate Tablets

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

Hyoscyamine Sulfate Tablets contain NLT 90.0% and NMT 110.0% of the labeled amount of hyoscyamine sulfate [(C₃₄H₄₈NO₁₀) · H₂SO₄ · 2H₂O].

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.

B. Identification Tests—General, Sulfate 〈191〉: A filtered solution of Tablets meets the requirements of the tests.

3 ASSAY

Procedure

Buffer: Transfer 13.6 g of monobasic potassium phosphate to a 2000-mL volumetric flask, dissolve in about 1800 mL of water, and adjust with phosphoric acid to a pH of 3.0 ± 0.1. Dilute with water to volume, and filter.

Mobile phase: With continuous stirring, add 0.3 mL of triethylamine to 1800 mL of Buffer. Add 200 mL of acetonitrile and degas.

Diluent: 0.01 N hydrochloric acid

Standard stock solution: 0.16 mg/mL of anhydrous hyoscyamine sulfate from USP Hyoscyamine Sulfate RS in Diluent.

[Note—This solution may be stored in a refrigerator for 30 days.]

Standard solution: 4.8 µg/mL of anhydrous hyoscyamine sulfate from the Standard stock solution in Diluent

Tropic acid solution: 3 µg/mL of tropic acid in Diluent

System suitability solution: Transfer 3.0 mL of the Standard stock solution into a 100-mL volumetric flask, add 4.0 mL of the Tropic acid solution, and dilute with Diluent to volume.

Sample solution: Finely powder NLT 20 Tablets. Transfer a quantity of the powder equivalent to 0.125 mg of hyoscyamine sulfate to a 25-mL volumetric flask. Add 20 mL of Diluent, and sonicate for 15 min with occasional swirling. Allow to cool to room temperature, and dilute with Diluent to volume. Pass an aliquot through a suitable filter of 0.45-µm pore size, and discard the first 5 mL of the filtrate.

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 205 nm

Columns

Guard: 3-mm × 4-mm; packing L11

Analytical: 4.6-mm × 15-cm; 4-µm packing L11

Column temperature: 30°

Flow rate: 1.0 mL/min

Injection volume: 50 µL

System suitability

Sample: System suitability solution

[Note—The elution order is the tropic acid peak, followed by the hyoscyamine peak.]

Suitability requirements

Resolution: NLT 1.5 between tropic acid and hyoscyamine

Tailing factor: NMT 1.8 for the hyoscyamine peak

Relative standard deviation: NMT 2.0% for six replicate injections

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of hyoscyamine sulfate

[(C₃₄H₄₈NO₁₀) · H₂SO₄ · 2H₂O] in the portion of Tablets taken:

Result = (rᵤ / rₛ) × (Cₛ / Cᵤ) × (M₁ / M₂) × 100

rᵤ = peak response from the Sample solution

rₛ = peak response from the Standard solution

Cₛ = concentration of anhydrous hyoscyamine sulfate in the Standard solution (µg/mL)

Cᵤ = nominal concentration of hyoscyamine sulfate in the Sample solution (µg/mL)

M₁ = molecular weight of hyoscyamine sulfate, 712.85

M₂ = molecular weight of anhydrous hyoscyamine sulfate, 676.83

Acceptance criteria: 90.0%–110.0%

4 PERFORMANCE TESTS

Disintegration 〈701〉: 15 min

Uniformity of Dosage Units 〈905〉: Meet the requirements

5 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight, light-resistant containers.

USP Reference Standards 〈11〉

USP Hyoscyamine Sulfate RS