Dexpanthenol

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 

Dexpanthenol contains NLT 98.0% and NMT 102.0% of dexpanthanol (C₉H₁₉NO₄), calculated on the anhydrous basis.

2 IDENTIFICATION 

Change to read: 

2.1 A. Spectroscopic Identification Tests 〈197〉, Infrared Spectroscopy: 197F (CN 1-May-2020) 

2.2 B. 

Sample solution: 100 mg/mL of Dexpanthenol 

Analysis: To 1 mL of the Sample solution add 5 mL of 1 N sodium hydroxide and 1 drop of cupric sulfate TS, and shake vigorously. Acceptance criteria: A deep blue color develops. 

2.3 C. 

Sample solution: 10 mg/mL of Dexpanthenol 

Analysis: To 1 mL of the Sample solution add 1 mL of 1 N hydrochloric acid, and heat on a steam bath for 30 min. Cool, add 100 mg of hydroxylamine hydrochloride, and add 5 mL of 1 N sodium hydroxide. Allow to stand for 5 min, then adjust with 1 N hydrochloric acid to a pH of 2.5–3.0, and add 1 drop of ferric chloride TS. 

Acceptance criteria: A purplish red color develops. 

3 ASSAY 

3.1 Procedure 

0.1 M potassium biphthalate: Transfer 20.42 g of potassium biphthalate into a 1000-mL volumetric ask, and add sucient glacial acetic acid to dissolve. If necessary, warm the mixture on a steam bath to achieve complete solution, observing precautions against absorption of moisture. Cool to room temperature, and dilute with glacial acetic acid to volume. 

Sample: 400 mg of Dexpanthenol 

Blank: Proceed as directed in the Analysis, omitting the Sample. 

Titrimetric system 

(See Titrimetry 〈541〉.) 

Mode: Residual titration 

Titrant: 0.1 N perchloric acid VS 

Back-titrant: 0.1 M potassium biphthalate 

Endpoint detection: Visual 

Analysis: Transfer the Sample to a 300-mL ask tted to a reux condenser by means of a standard-taper glass joint, add 50.0 mL of Titrant, and reux for 5 h. Cool, observing precautions to prevent atmospheric moisture from entering the condenser, and rinse the condenser with glacial acetic acid, collecting the rinsings in the ask. To the ask, add 5 drops of crystal violet TS, and titrate with the Back-titrant to a blue green endpoint. Perform the Blank determination. 

Calculate the percentage of dexpanthenol (C₉H₁₉NO₄) in the Sample taken: 

Result = {[(V_B − V_S) × M × F]/W} × 100 

V_B = Back-titrant volume consumed by the Blank (mL) 

V_S = Back-titrant volume consumed by the Sample (mL) 

M = actual molarity of the Back-titrant (mM/mL) 

F = equivalency factor, 205.3 mg/mM 

W = Sample weight (mg) 

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

4 IMPURITIES 

4.1 Residue on Ignition 〈281〉: NMT 0.1% 

4.2 Limit of Aminopropanol 

Sample: 5 g of Dexpanthenol 

Blank: 10 mL of water 

Titrimetric system 

(See Titrimetry 〈541〉.) 

Mode: Direct titration 

Titrant: 0.1 N sulfuric acid VS 

Endpoint detection: Visual 

Analysis: Dissolve the Sample in 10 mL of water, and add bromothymol blue TS. Titrate with the Titrant to a yellow endpoint. Perform the Blank determination. 

Calculate the percentage of aminopropanol in the Sample taken: 

Result = {[(V_S − V_B) × N × F]/W} × 100 

V_S = Titrant volume consumed by the Sample (mL) 

V_B = Titrant volume consumed by the Blank (mL) 

N = actual normality of the Titrant (mEq/mL) 

F = equivalency factor, 75.11 mg/mEq 

W = Sample weight (mg) 

Acceptance criteria: NMT 1.0% 

5 SPECIFIC TESTS 

5.1 Optical Rotation, Specific Rotation〈781S〉 

Sample solution: 50 mg/mL in water 

Acceptance criteria: +29.0° to +31.5° 

5.2 Refractive Index 〈831〉: 1.495–1.502, at 20° 

5.3 Water Determination, Method I〈921〉: NMT 1.0% 

6 ADDITIONAL REQUIREMENTS 

6.1 Packaging and Storage: Preserve in tight containers. 

6.2 USP Reference Standards 〈11〉 

USP Dexpanthenol RS