Dexpanthenol Preparation
If you find any inaccurate information, please let us know by providing your feedback here
Tóm tắt nội dung
This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition
Issued and maintained by the United States Pharmacopeial Convention (USP)
1 DEFINITION
Dexpanthenol Preparation contains NLT 94.5% and NMT 98.5% of dexpanthenol (C9H19NO4), and NLT 2.7% and NMT 4.2% of pantolactone, both calculated on the anhydrous basis.
2 IDENTIFICATION
Change to read:
2.1 A. Spectroscopic Identification Tests 〈197〉, Infrared Spectroscopy: 197F (USP 1-Dec-2021)
Acceptance criteria: The IR absorption spectrum of a thin lm of Preparation exhibits maxima only at the same wavelengths as that of USP Dexpanthenol RS, except that there is an additional maximum at 5.6 µm due to pantolactone.
2.2 B.
Sample solution: 100 mg/mL of Preparation
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.
3 COMPOSITION
3.1 Content of Dexpanthenol
Sample: 400 mg of Preparation
Blank: Prepare 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 prepared as follows. 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.
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. Add 5 drops of crystal violet TS to the ask and titrate with the Back titrant to a blue green endpoint. Perform a blank determination.
Calculate the percentage of dexpanthenol (C9H19NO4) in the Sample taken:
Result = {[(VB − VS) × M × F]/W} × 100
VB = Back titrant volume consumed by the Blank (mL)
VS = 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 = weight of the Sample (mg)
Acceptance criteria: 94.5%–98.5% on the anhydrous basis
Change to read:
3.2 Content of Pantolactone
Internal standard solution: 100 mg/mL of 2,6-dimethylphenol in toluene
Standard stock solution: 10 mg/mL of USP Pantolactone RS in methylene chloride
Standard solution: Pipet 0.4 mL of Standard stock solution into a suitable small vial. Evaporate the solvent by means of a steady stream of dry air, and add 50.0 µL of Internal standard solution. Add 1 mL of a mixture of pyridine, hexamethyldisilazane, and trimethylchlorosilane (9:3:1), immediately close the vial, and shake vigorously for 30 s.
Sample solution: Transfer 100 mg of Preparation to a suitable small vial and prepare as directed for the Standard solution, beginning with “add 50.0 µL of Internal standard solution”.
Chromatographic system
(See Chromatography 〈621〉, System Suitability.)
Mode: GC
Detector: Flame ionization
Column: 2.0-mm × 1.8-m; packed with 5% liquid phase G2 on support S1A
Temperatures
Detector: 180°(USP 1-Dec-2021)
Injection port: 180°
Column: 170°, isothermal
Flow rate: Using a suitable carrier gas, adjust the ow rate so that the derivatized pantolactone elutes in 4 min.
Injection volume: 0.5 µL
System suitability
Sample: Standard solution
[Note—The relative retention times for derivatized pantolactone and derivatized internal standard are 0.75 and 1.0, respectively.]
Suitability requirements
Resolution: NLT 2.0 between derivatized pantolactone and the derivatized internal standard
Relative standard deviation: NMT 2.0% for the ratio of the peak response of derivatized pantolactone to the peak response of the derivatized internal standard
Analysis
Samples: Standard solution and Sample solution
Calculate the percentage of pantolactone in the portion of Preparation taken:
Result = (Ru/Rs) × (V/W) × Cs × 100
Ru = internal standard ratio (peak response of derivatized pantolactone/peak response of derivatized internal standard) from the Sample solution
Rs = internal standard ratio (peak response of derivatized pantolactone/peak response of derivatized internal standard) from the Standard solution
V = volume of the Standard stock solution taken to prepare the Standard solution, 0.4 mL
W = weight of Preparation taken to prepare the Sample solution (mg)
Cs = concentration of USP Pantolactone RS in the Standard stock solution (mg/mL)
Acceptance criteria: 2.7%–4.2% on the anhydrous basis
4 IMPURITIES
4.1 Residue on Ignition 〈281〉: NMT 0.1%
4.2 Limit of Aminopropanol
Sample: 5 g of Preparation
Blank: 10 mL of water
Titrimetric system
(See Titrimetry 〈541〉.)
Mode: Direct titration
Titrant: 0.1 N sulfuric acid prepared from 1 N sulfuric acid VS by dilution
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 a blank determination.
Calculate the percentage of aminopropanol in the Sample taken:
Result = {[(VS − VB) × N × F]/W} × 100
VS = Titrant volume consumed by the Sample (mL)
VB = 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 〈781S〉, Procedures, Specific Rotation
Sample solution: 50 mg/mL in water
Acceptance criteria: +27.5° to +30.0°
5.2 Refractive Index 〈831〉: 1.495–1.502, at 20°
5.3 Water Determination 〈921〉, Method I: NMT 1.0%
6 ADDITIONAL REQUIREMENTS
6.1 Packaging and Storage: Preserve in tight containers.
6.2 USP Reference Standards 〈11〉
USP Dexpanthenol RS
USP Pantolactone RS
