Dicyclomine Hydrochloride Capsules

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 Capsules contain NLT 93.0% and NMT 107.0% of the labeled amount of dicyclomine hydrochloride (C₁₉H₃₅NO₂ . HCl). 

2 IDENTIFICATION 

2.1 A. 

Sample: Transfer a portion of the contents of the Capsules, equivalent to 100 mg of dicyclomine hydrochloride, to a separator containing 10 mL of water and 1 mL of hydrochloric acid. 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. 

2.2 B.

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

3 ASSAY 

Change to read: 

3.1 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 water (70:30) 

Standard solution: 0.4 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: Remove, as completely as possible, the contents of NLT 20 Capsules, and mix the contents. Transfer a portion of the powder, equivalent to 20 mg of dicyclomine hydrochloride, to a 50-mL volumetric ask, add 2.0 mL of water, and sonicate for at least 2 min to disperse the sample. Add 35 mL of acetonitrile, sonicate for at least 5 min, and shake by mechanical means for at least 30 min. Add 10 mL of water, allow the solution to equilibrate to room temperature, then dilute with water to volume. Centrifuge a portion of this solution in a 15-mL glass centrifuge tube for at least 5 min. Use the clear supernatant. 

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 Capsules 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: 93.0%–107.0% 

4 PERFORMANCE TESTS 

Change to read: 

4.1 Dissolution 〈711〉 

Medium: 0.01 N hydrochloric acid; 500 mL 

Apparatus 2: 50 rpm 

Time: 45 min 

Determine the amount of dicyclomine hydrochloride (C₁₉H₃₅NO₂ . HCl) dissolved by employing the following method.

Buffer: Dissolve 2.72 g of monobasic potassium phosphate in 450 mL of water, adjust with 10% sodium hydroxide to a pH of 7.5 ± 0.1, and dilute to 500 mL. 

Mobile phase: Prepare as directed in the Assay. 

Diluent: Acetonitrile and Buffer (1:1) 

Standard stock solution: 20 µg/mL of USP Dicyclomine Hydrochloride RS in Medium 

Standard solution: Mix 25.0 mL of Standard stock solution and 25.0 mL of Diluent. 

Sample solution: Pass a portion of the solution under test through a glass microber lter of 0.7-µm pore size. Transfer 5.0 mL of the ltrate to a suitable ask, and add 5.0 mL of 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 (USP 1-Dec-2020) mL/min 

Injection volume: 250 µL 

System suitability 

Sample: Standard solution 

Suitability requirements 

Tailing factor: NMT 2.0 

Relative standard deviation: 2.0% 

Analysis 

Samples: Standard solution and Sample solution 

Calculate the percentage of the labeled amount of dicyclomine hydrochloride (C₁₉H₃₅NO₂ . HCl) dissolved: 

Result = (r_u/r_s) × (C_s/L) × V × D × 100 

r_u = peak response of dicyclomine 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) 

L = label claim (mg/Capsule) 

V = volume of Medium, 500 mL 

D = dilution factor for the Sample solution (USP 1-Dec-2020) 

Tolerances: NLT 75% (Q) of the labeled amount of dicyclomine hydrochloride (C₁₉H₃₅NO₂ . HCl) is dissolved. 

4.2 Uniformity of Dosage Units 〈905〉: Meet the requirements 

5 IMPURITIES 

Add the following: 

5.1 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 (70:30) 

Standard stock solution: 0.1 mg/mL of USP Dicyclomine Related Compound A RS in Diluent. Sonication may be used. Standard solution: 4.0 µg/mL of USP Dicyclomine Related Compound A RS in Diluent from Standard stock solution Sensitivity solution: 2.0 µg/mL of USP Dicyclomine Related Compound A RS in Diluent from Standard solution 

Sample solution: Nominally 2.0 mg/mL of dicyclomine hydrochloride in Diluent prepared as follows. Remove, as completely as possible, the contents of NLT 20 Capsules, and mix the contents. Transfer a portion of the powder, equivalent to 200 mg of dicyclomine hydrochloride, to a 100-mL volumetric ask, add about 10 mL of water, and sonicate for at least 2 min to disperse the sample. Add 70 mL of acetonitrile, sonicate for at least 5 min, and shake by mechanical means for at least 30 min. Add 10 mL of water, allow the solution to equilibrate to room temperature, then dilute with water to volume. Centrifuge a portion of this solution, and use the supernatant. 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 Capsules 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) 

6 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 

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

C₁₃H₂₂O₂       210.32 

(USP 1-Dec-2020)