Cyanocobalamin Tablets

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

Cyanocobalamin Tablets contain NLT 90.0% and NMT 110.0% of the labeled amount of cyanocobalamin (C₆₃H₈₈CON₁₄O₁₄P).

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, Procedure 1 or Procedure 2.

3 ASSAY

[NOTE-Where more than one assay procedure is given in the monograph, the requirements may be met by following any one of the specified procedures. The procedure used is stated in the labeling only if Procedure 1 is not used.]

3.1 PROCEDURE 1

[NOTE-Use low-actinic glassware throughout this procedure.]

Mobile phase: Methanol and water (7:13)

Standard solution: 5 µg/mL of cyanocobalamin from USP Cyanocobalamin (Crystalline) RS in water

Sample solution: Finely powder NLT 30 Tablets. Transfer a portion of the powder, equivalent to 500 µg of cyanocobalamin, to a 100-mL volumetric flask, add 60 mL of water, and sonicate for 5 min. Dilute with water to volume, and filter.

Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: LC

Detector: 361 nm

Column: 4.6-mm x 15-cm; 5-µm packing L1

Flow rate: 0.5 mL/min

Injection volume: 100 µL

System suitability

Sample: Standard solution

Suitability requirements

Relative standard deviation: NMT 2.0%

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of cyanocobalamin (C₆₃H₈₈CON₁₄O₁₄P) in the portion of Tablets taken: 

Result = (r_u/r_s) × (C_s/C_u) × 100

r_u = peak response from the Sample solution

r_s = peak response from the Standard solution

C_s = concentration of cyanocobalamin from USP Cyanocobalamin (Crystalline) RS in the Standard solution (µg/mL)

C_u = nominal concentration of cyanocobalamin in the Sample solution (µg/mL)

Acceptance criteria: 90.0%-110.0%

3.2 PROCEDURE 2

[NOTE-Use low-actinic glassware throughout this procedure. Inject samples within 30 min.]

Buffer: Dissolve 470.5 mg of low UV hexanesulfonic acid sodium salt in water, add 1 mL of phosphoric acid, dilute with water to 1000 mL, and mix. Adjust with 50% potassium hydroxide to a pH of 3.5.

Mobile phase: Acetonitrile and Buffer. See Table 1 for gradient.

Table 1

Standard solution: 1 µg/mL of cyanocobalamin from USP Cyanocobalamin (Crystalline) RS in water

Sample solution: Finely powder NLT 20 Tablets. Transfer a portion of the powder, equivalent to 25 µg of cyanocobalamin, to a suitable Erlenmeyer flask with a stopper, pipet 25 mL of water, sonicate for 5 min, and shake vigorously for 2 min. Pass through a membrane filter of 0.45-µm pore size.

Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: UPLC

Detector: UV 361 nm

Column: 2.1 - mm x 10 - 6 cm; 1.7-µm packing L1

Column temperature: 35°

Flow rate: 0.5 mL/min

Injection volume: 15 µL

System suitability

Sample: Standard solution

Suitability requirements

Relative standard deviation: NMT 2.0%

Analysis

Samples: Standard solution and Sample solution

OFFICIAL

1414 Calculate the percentage of the labeled amount of cyanocobalamin (C₆₃H₈₈CON₁₄O₁₄P) in the portion of Tablets taken: 

Result = (r_u/r_s) × (C_s/C_u) × 100

r_u = peak response from the Sample solution

r_s = peak response from the Standard solution S

C_s = concentration of cyanocobalamin from USP Cyanocobalamin (Crystalline) RS in the Standard solution (µg/mL)

C_u = nominal concentration of cyanocobalamin in the Sample solution (µg/mL)

Acceptance criteria: 90.0%-110.0%

4 PERFORMANCE TESTS

4.1 DISINTEGRATION (701)

Medium: Water

Time: 30 min. If the label recommends to disintegrate the Tablets in the mouth before swallowing: NMT 3 min

Acceptance criteria: Meet the requirements

4.2 UNIFORMITY OF DOSAGE UNITS (905):

Meet the requirements

5 ADDITIONAL REQUIREMENTS

5.1 PACKAGING AND STORAGE:

Preserve in tight, light-resistant containers.

5.2 LABELING:

Tablets that are intended to be disintegrated in the mouth before swallowing are so labeled. The labeling states with which assay procedure the product complies only if Procedure 1 is not used.

5.3 USP REFERENCE STANDARDS (11)

USP Cyanocobalamin (Crystalline) RS