Diphenhydramine EP Impurity B CAS 19804-27-4

Purity >95%In StockPharmacopoeial Impurity Standards
CAS No.19804-27-4
Molecular FormulaC18H23NO
Molecular Weight269.38 g/mol
CategoryPharmacopoeial Impurity Standards / EP Impurities
AvailabilityIn Stock

Chemical Structure

Diphenhydramine EP Impurity B CAS 19804-27-4 chemical structure

Description

Structurally, Diphenhydramine EP Impurity B (C18H23NO) contains a steroid core, an amide group, a hydroxyl group, an ether linkage. The molecule exhibits a degree of unsaturation (DBE) of 8.0, corresponding to approximately 8 ring(s) or double-bond equivalent(s). With a molecular weight of 269.38 g/mol, it falls into the medium-molecular-weight range. The presence of an aromatic ring or conjugated system gives the compound characteristic absorption bands in the UV-Vis region, making it well suited to UV or diode-array detection (DAD).

Diphenhydramine EP Impurity B (CAS 19804-27-4) is a certified pharmaceutical impurity reference standard with the molecular formula C18H23NO and a molecular weight of 269.38 g/mol.

This reference standard supports related-substances testing and method development in line with ICH Q3A/Q3B guidance on impurity control, and is suitable for system suitability testing and forced-degradation studies.

The assigned purity is verified by mass-balance and quantitative NMR (qNMR) approaches, with the expanded uncertainty reported at a 95% confidence level (k=2). Batch homogeneity and stability are independently assessed for every lot.

Physical & Chemical Properties

Molecular FormulaC18H23NO
Molecular Weight269.38 g/mol
Purity>95%
StorageStore at 2-8°C, protect from light
Solubility (reference)Soluble in chloroform, dichloromethane, ethyl acetate, DMSO
StabilityLight-sensitive; avoid direct strong light
Degree of Unsaturation (DBE)8.0
UV AbsorptionUV-absorbing
Structural FeaturesAromatic ring present
CAS Registry Year (est.)1962
Nitrogen Atoms1

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