Cholecalciferol 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

Cholecalciferol Capsules contain a solution of Cholecalciferol in an edible oil or other suitable vehicle. Cholecalciferol Capsules contain NLT 90.0% and NMT 110.0% of the labeled amount of vitamin D as cholecalciferol (C₂₇H₄₄O).

2 IDENTIFICATION

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

3 ASSAY

Change to read:

3.1 PROCEDURE

[NOTE—Use low-actinic glassware throughout this procedure.] Mobile phase: n-Hexane and isopropyl alcohol (99:1)

System suitability solution: 250 mg of USP Vitamin D Assay System Suitability RS in 10 mL of n-hexane. Heat this solution under reflux, at 60° for 1 h, and cool. [NOTE—This solution contains cholecalciferol, precholecalciferol, and trans-cholecalciferol.]

Standard stock solution: 50 µg/mL of USP Cholecalciferol RS in n-hexane. [NOTE—Prepare solution fresh daily.] Standard solution A: 5 µg/mL of USP Cholecalciferol RS in n-hexane from the Standard stock solution

Standard solution B: Transfer a 5-mL volume of the Standard stock solution to a container having a polytef-lined screw cap. Displace the air with nitrogen and heat at 60° for 1 h under a nitrogen atmosphere, and cool. Quantitatively transfer the solution to a 50-mL volumetric flask, and dilute with n-hexane to volume.

Sample solution: Weigh NLT 30 Capsules in a tared weighing bottle. With a sharp blade or by other appropriate means, carefully open the Capsules, without loss of the shell material, and transfer as much as possible of the combined Capsule contents to a suitable container. Remove any adhering substance from the emptied Capsules and shell remains by washing with several small portions of n-hexane. Discard the washings, and allow the empty Capsules and shell remains to dry in a current of dry air until the odor of n-hexane is no longer perceptible. Weigh the empty Capsules and shell remains in the original tared weighing bottle, and calculate the average net weight per Capsule by difference. Dissolve a portion of the combined Capsule contents in n-hexane to prepare a cholecalciferol solution with a nominal concentration of 5 µg/mL.

3.1.1 Chromatographic system

(See Chromatography 〈621〉, System Suitability.) Mode: LC

Detector: UV 265 nm

Column: 4.6-mm × 15-cm; 3-µm packing L8 Flow rate: 1 mL/min

Injection volume: 10 µL

3.1.2 System suitability

Sample: System suitability solution

[NOTE—The relative retention times for precholecalciferol, trans-cholecalciferol, and cholecalciferol are 0.5, 0.6, and 1.0, respectively.]

Suitability requirements

Resolution: NLT 1.0 (USP 1-Aug-2019) between trans-cholecalciferol and precholecalciferol Relative standard deviation: NMT 2.0% for cholecalciferol

3.1.3 Analysis

Samples: Standard solution A, Standard solution B, and Sample solution

Cholecalciferol response factor

Calculate the Cholecalciferol response factor (F_C):

F_C = C_s/r_s

C_s = concentration of USP Cholecalciferol RS in Standard solution A (µg/mL)

r_s = peak area of cholecalciferol from Standard solution A

Precholecalciferol response factor

Calculate the concentration of cholecalciferol (C′_s), in µg/mL, in Standard solution B:

C'_s = F_C × r'_s

F_C = Cholecalciferol response factor, as previously determined

r'_s = peak area of cholecalciferol from Standard solution B

Calculate the concentration of precholecalciferol (C′_pre), in µg/mL, in Standard solution B:

C′_pre = C_s − C′_s

C_s = concentration of USP Cholecalciferol RS in Standard solution A (µg/mL)

C′_s = concentration of cholecalciferol in Standard solution B (µg/mL)

Calculate the Precholecalciferol response factor (F_pre):

F_pre = C′_pre/r_p

C′_pre = concentration of precholecalciferol in Standard solution B (µg/mL)

r_p = peak response of precholecalciferol from Standard solution B

Vitamin D content

Calculate the percentage of the labeled amount of vitamin D as cholecalciferol (C₂₇H₄₄O) in the portion of Capsules taken:

Result = {[(F_C × r_C) + (F_pre × r_pre)]/C_U} × 100

F_C = Cholecalciferol response factor, as previously determined

r_C = peak area of cholecalciferol from the Sample solution

F_pre = Precholecalciferol response factor, as previously determined

r_pre = peak area of precholecalciferol from the Sample solution

C_U = nominal concentration of cholecalciferol in the Sample solution (µg/mL)

Acceptance criteria: 90.0%–110.0%

4 PERFORMANCE TESTS

DISINTEGRATION 〈701〉

Buffer solution: 0.05 M acetate buffer, prepared by mixing 2.99 g of sodium acetate and 1.66 mL of glacial acetic acid with water to obtain a 1000-mL solution having a pH of 4.5 ± 0.05

Immersion fluid: Buffer solution Time: 45 min

Acceptance criteria: Meet the requirements

UNIFORMITY OF DOSAGE UNITS 〈905〉: Meet the requirements

5 ADDITIONAL REQUIREMENTS

PACKAGING AND STORAGE: Preserve in tight, light-resistant containers. Change to read:

LABELING: Label the Capsules to indicate the content of cholecalciferol in micrograms. Expression of the amount of cholecalciferol in terms of units may be added in parentheses after the mass units.¹ (USP 1-Aug-2019)

USP REFERENCE STANDARDS 〈11〉

USP Cholecalciferol RS

USP Vitamin D Assay System Suitability RS

¹ Where articles are labeled in terms of units in addition to the required labeling, the relationship of the USP Units or International Units (IU) to mass units is as follows: 1 μg of cholecalciferol or ergocalciferol = 40 USP Units or IU.