Hyoscyamine Sulfate 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

Hyoscyamine Sulfate Oral Solution contains 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.

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, 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

Sample solution: 5 µg/mL of hyoscyamine sulfate from an appropriate volume of Oral Solution in Diluent. 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: Standard solution

Suitability requirements

Tailing factor: NMT 1.8

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 Oral Solution 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

Uniformity of Dosage Units 〈905〉

For single-unit containers

Acceptance criteria: Meets the requirements

Deliverable Volume 〈698〉

For multiple-unit containers

Acceptance criteria: Meets the requirements

5 SPECIFIC TESTS

pH 〈791〉: 3.0–6.5

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight, light-resistant containers, and store at controlled room temperature.

USP Reference Standards 〈11〉

USP Hyoscyamine Sulfate RS