Dicyclomine Hydrochloride

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 

Dicyclomine Hydrochloride contains NLT 98.0% and NMT 102.0% of dicyclomine hydrochloride (C₁₉H₃₅NO₂ . HCl), calculated on the dried basis. 

2 IDENTIFICATION  

A. Spectroscopic Identification Tests 〈197〉, Infrared Spectroscopy: 197K or 197A 

Change to read: 

B. Identification Tests—General 〈191〉, Chemical Identification Tests, Chloride: Meets the requirements of the test for amine hydrochlorides (ERR 1-Feb-2024) 

C. 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 

Buffer: Dissolve 2.72 g of monobasic potassium phosphate in 900 mL of water, adjust with 10% sodium hydroxide solution to a pH of 7.5, and dilute with water to 1000 mL. 

Mobile phase: Acetonitrile and Buffer (70:30) 

Diluent: Acetonitrile and water (70:30) 

Standard solution: 0.4 mg/mL of USP Dicyclomine Hydrochloride RS in Diluent. [Note—This solution is stable for at least 2 days.]

Sample solution: 0.4 mg/mL of Dicyclomine Hydrochloride in Diluent 

Chromatographic system 

(See Chromatography 〈621〉, System Suitability.) 

Mode: LC 

Detector: UV 215 nm 

Column: 4.6-mm × 15-cm; 3.5-µm packing L7 

Flow rate: 1 mL/min 

Injection volume: 50 µL 

System suitability 

Sample: Standard solution 

Suitability requirements 

Tailing factor: NMT 1.5 

Relative standard deviation: NMT 0.73% 

Analysis 

Samples: Standard solution and Sample solution 

Calculate the percentage of dicyclomine hydrochloride (C₁₉H₃₅NO₂ . HCl) in the portion of Dicyclomine Hydrochloride taken: 19 35 2 

Result = (r_u/r_s) × (C_s/C_u) × 100

r_u = peak area of dicyclomine from the Sample solution  

r_s = peak area of dicyclomine from the Standard solution 

C_s = concentration of USP Dicyclomine Hydrochloride RS in the Standard solution (mg/mL) 

C_u = concentration of Dicyclomine Hydrochloride in the Sample solution (mg/mL) 

Acceptance criteria: 98.0%–102.0% on the dried basis 

4 IMPURITIES 

4.1 Organic Impurities 

Buffer, Mobile phase, Diluent, Sample solution, and Chromatographic system: Proceed as directed in the Assay. Standard stock solution: Use the Standard solution from the Assay. 

Standard solution: 0.4 µg/mL of USP Dicyclomine Hydrochloride RS in Diluent from Standard stock solution 

Sensitivity solution: 0.2 µg/mL of USP Dicyclomine Hydrochloride RS in Diluent from Standard solution 

System suitability 

Samples: Standard stock solution, Standard solution, and Sensitivity solution 

[Note—USP Dicyclomine Hydrochloride RS contains dicyclomine-1′-ene as a minor component.] 

Suitability requirements 

Resolution: NLT 2.0 between dicyclomine and dicyclomine-1′-ene, Standard stock solution 

Relative standard deviation: NMT 5.0%, Standard solution 

Signal-to-noise ratio: NLT 10, Sensitivity solution 

Analysis 

Samples: Standard solution and Sample solution 

Calculate the percentage of each individual impurity in the portion of Dicyclomine Hydrochloride taken: 

Result = (r_u/r_s) × (C_s/C_u) × (1/F) × 100 

r_u = peak response of each impurity from the Sample solution 

r_s = peak response of dicyclomine from the Standard solution 

C_s = concentration of USP Dicyclomine Hydrochloride RS in the Standard solution (mg/mL) 

C_u = concentration of Dicyclomine Hydrochloride in the Sample solution (mg/mL) 

F = relative response factor (see Table 1) 

Acceptance criteria: See Table 1. The reporting threshold is 0.05%. 

Table 1 

a 2-(Diethylamino)ethyl [1,1′-bi(cyclohexan)]-1′-ene-1-carboxylate. 

4.2 Limit of Dicyclomine Related Compound A 

Buffer: Dissolve 2.72 g of monobasic potassium phosphate in 900 mL of water, adjust with phosphoric acid to a pH of 3.5, and dilute with water to 1000 mL. 

Mobile phase: Acetonitrile and Buffer (55:45) 

Diluent: Acetonitrile and water (70:30) 

Standard stock solution: 0.1 mg/mL of USP Dicyclomine Related Compound A RS in Diluent. Sonication may be used.

Standard solution: 3.0 µg/mL of USP Dicyclomine Related Compound A RS in Diluent from Standard stock solution

Sensitivity solution: 1.5 µg/mL of USP Dicyclomine Related Compound A RS in Diluent from Standard solution 

Sample solution: 2.0 mg/mL of Dicyclomine Hydrochloride in Diluent. Sonication may be used. 

Chromatographic system 

(See Chromatography 〈621〉, System Suitability.) 

Mode: LC 

Detector: UV 215 nm 

Column: 4.6-mm × 15-cm; 3.5-µm packing L7 

Flow rate: 1 mL/min 

Injection volume: 100 µL 

System suitability 

Samples: Standard solution and Sensitivity solution 

Suitability requirements 

Relative standard deviation: NMT 5.0%, Standard solution 

Signal-to-noise ratio: NLT 10, Sensitivity solution 

Analysis 

Samples: Standard solution and Sample solution 

Calculate the percentage of dicyclomine related compound A in the portion of Dicyclomine Hydrochloride taken: 

Result = (r_u/r_s) × (C_s/C_u) × 100

r_u = peak response of dicyclomine related compound A from the Sample solution 

r_s = peak response of dicyclomine related compound A from the Standard solution 

C_s = concentration of USP Dicyclomine Related Compound A RS in the Standard solution (mg/mL) 

C_u = concentration of Dicyclomine Hydrochloride in the Sample solution (mg/mL) 

Acceptance criteria 

Dicyclomine related compound A: NMT 0.20% 

Total impurities: The sum of all the impurities found in the Limit of Dicyclomine Related Compound A and Organic Impurities tests is NMT 0.7%. 

5 SPECIFIC TESTS 

5.1 pH 〈791〉 

Sample solution: 10 mg/mL

Acceptance criteria: 5.0–5.5

5.2 Loss on Drying 〈731〉 

Analysis: Dry at 105° for 4 h.

Acceptance criteria: NMT 1.0% 

6 ADDITIONAL REQUIREMENTS 

6.1 Packaging and Storage:

Preserve in well-closed containers. 

6.2 USP Reference Standards 〈11〉 

USP Dicyclomine Hydrochloride RS 

USP Dicyclomine Related Compound A RS 

[1,1′-Bi(cyclohexane)]-1-carboxylic acid. 

C₁₃H₂₂O₂         210.32