Dicyclomine Hydrochloride 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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DEFINITION 

Dicyclomine Hydrochloride Oral Solution contains NLT 95.0% and NMT 105.0% of the labeled amount of dicyclomine hydrochloride (C₁₉H₃₅NO₂ . HCl). 

1 IDENTIFICATION 

1.1 A. 

Sample: Transfer a portion of Oral Solution, equivalent to 100 mg of dicyclomine hydrochloride, to a separator containing 10 mL of water and 1 mL of hydrochloric acid. Extract with two 30-mL portions of ether, and discard the ether. Extract the aqueous acid solution with two 30-mL portions of chloroform, transfer the chloroform extracts to a second separator containing 20 mL of water and 1 mL of sodium hydroxide solution (1 in 10), and shake. Filter the chloroform layer through anhydrous sodium sulfate into a suitable container. Add 3 mL of a freshly prepared 1-in-20 solution of acetyl chloride in anhydrous methanol, prepared by cautiously adding acetyl chloride dropwise to anhydrous methanol with stirring. Evaporate under reduced pressure at room temperature until the residue has been thoroughly dried. Use the residue so obtained to prepare a potassium bromide dispersion. 

Standard: Use a similarly prepared potassium bromide dispersion of USP Dicyclomine Hydrochloride RS. 

Acceptance criteria: The IR absorption spectrum of the Sample exhibits maxima and minima at the same wavelengths as those of the Standard. 

1.2 B.

The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay. 

2 ASSAY 

Change to read: 

2.1 Procedure 

Buffer: Dissolve 2.72 g of monobasic potassium phosphate in 900 mL of water, adjust with 10% sodium hydroxide to a pH of 7.5 ± 0.1, and dilute with water to 1000 mL. 

Mobile phase: Acetonitrile and Buffer (70:30) 

Diluent: Acetonitrile and Buffer (35:65) 

Standard solution: 0.1 mg/mL of USP Dicyclomine Hydrochloride RS in Diluent. [Note—This solution is stable for at least (USP 1-Dec-2020) 2 days.] 

Sample solution: Using a “to contain” pipet, transfer a measured volume of Oral Solution, equivalent to 10.0 mg of dicyclomine hydrochloride, to a 100-mL volumetric ask. Rinse the pipet with several small portions of Diluent, and add the rinsings to the volumetric ask. Dilute with Diluent to volume. 

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 (USP 1-Dec-2020) mL/min 

Injection volume: 50 µL 

System suitability 

Sample: Standard solution 

Suitability requirements 

Tailing factor: NMT 1.5 

Relative standard deviation: NMT 1.5% 

Analysis 

Samples: Standard solution and Sample solution 

Calculate the percentage of the labeled amount of dicyclomine hydrochloride (C₁₉H₃₅NO₂ . HCl) in the portion of Oral Solution taken: 

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 = nominal concentration of dicyclomine hydrochloride in the Sample solution (mg/mL) 

Acceptance criteria: 95.0%–105.0% 

3 IMPURITIES 

Add the following: 

3.1 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. 

Solution A: Acetonitrile and Buffer (55:45) 

Solution B: Acetonitrile and Buffer (80:20) 

Mobile phase: See Table 1. 

Table 1 

Diluent: Acetonitrile and water (35:65) 

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

Standard solution: 2.0 µg/mL of USP Dicyclomine Related Compound A RS in Diluent from Standard stock solution

Sensitivity solution: 1.0 µg/mL of USP Dicyclomine Related Compound A RS in Diluent from Standard solution 

Sample solution: Nominally 1.0 mg/mL of dicyclomine hydrochloride in Diluent prepared as follows. Transfer a measured volume of Oral Solution, equivalent to 20 mg of dicyclomine hydrochloride, to a 20-mL volumetric ask. Rinse the pipet with several small portions of Diluent, and add the rinsings to the volumetric ask. Dilute with Diluent to volume. 

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 Oral Solution 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 = nominal concentration of dicyclomine hydrochloride in the Sample solution (mg/mL) 

Acceptance criteria: NMT 0.2%▲ (USP 1-Dec-2020) 

4 ADDITIONAL REQUIREMENTS 

Change to read: 

Packaging and Storage: Preserve in well-closed containers. Store at controlled room temperature. (USP 1-Dec-2020)

Change to read: 

USP Reference Standards 〈11〉 

USP Dicyclomine Hydrochloride RS 

USP Dicyclomine Related Compound A RS 

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

C₁₃H₂₂O₂           210.32 (USP 1-Dec-2020)