Ergocalciferol Oral Solution
DEFINITION
Ergocalciferol Oral Solution is a solution of Ergocalciferol in an edible vegetable oil, in Polysorbate 80, or in Propylene Glycol. It contains NLT 100.0% and NMT 120.0% of the labeled amount of vitamin D as ergocalciferol (C28H44O).
ASSAY
• Procedure
Mobile phase:
Chloroform containing alcohol as a preservative
Standard stock solution:
50 µg/mL of USP Ergocalciferol RS in chloroform. [NotePrepare this solution fresh daily. ]
Standard solution A:
5 µg/mL of USP Ergocalciferol RS from the Standard stock solution in chloroform. [NoteStore this Standard solution A at a temperature not above 0. ]
Standard solution B:
Transfer 5.0 mL of the Standard stock solution into a round-bottomed flask fitted with a reflux condenser. Displace the air with nitrogen, and reflux for 1 h in a water bath under a nitrogen atmosphere to obtain a solution containing ergocalciferol and pre-ergocalciferol. Cool, transfer, with the aid of several portions of chloroform, to a 50-mL volumetric flask, dilute with chloroform to volume, and mix.
Sample solution:
Equivalent to 5 µg/mL of ergocalciferol from an accurately measured volume of Oral Solution in chloroform
Chromatographic system
Mode:
LC
Detector:
UV 254 nm
Column:
4.6-mm × 25-cm; 5-µm packing L3
Flow rate:
1 mL/min
Injection size:
1020 µL
System suitability
Sample:
Standard solution B
[NoteThe relative retention times for pre-ergocalciferol and for ergocalciferol are 0.8 and 1.0, respectively. ]
Suitability requirements
Resolution:
NLT 1.0 between the pre-ergocalciferol peak and the ergocalciferol peak
Relative standard deviation:
NMT 2.0%
Analysis
Samples:
Standard solution A, Standard solution B, and Sample solution
Ergocalciferol response factor
Calculate the Ergocalciferol response factor, FD:
FD = CS/rS
Pre-ergocalciferol response factor
Calculate the concentration, C¢S, in µg/mL, of ergocalciferol in Standard solution B:
C¢S = FD × r¢S
Calculate the concentration, C¢pre, in µg/mL, of pre-ergocalciferol:
C¢pre = CS C¢S
Calculate the Pre-ergocalciferol response factor, Fpre:
Fpre = C¢pre/rp
Vitamin D content
Calculate the percentage of the labeled amount of vitamin D as ergocalciferol (C28H44O) in the portion of Oral Solution taken:
Result = {[(FD × rC) + (Fpre × rpre)]/CU} × 100
Acceptance criteria:
100.0%120.0%
ADDITIONAL REQUIREMENTS
• Packaging and Storage:
Preserve in tight, light-resistant containers.
• Labeling:
Label the Oral Solution to indicate the concentration of ergocalciferol, in mg per dosage unit. The activity may be expressed also in terms of USP Units, on the basis that 40 USP Vitamin D Units = 1 µg.
Auxiliary Information
Please check for your question in the FAQs before contacting USP.
USP35NF30 Page 3065
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