Establishment of a reference standard for epimedin C isolated from Herba Epimedii by mass-balance

Abstract

Herba Epimedii comprises the dried aerial parts of various Epimedium species (family Berberidaceae). This medicinal material is widely recognized for its pharmacological activities, including sexual function enhancement, anti-osteoporotic, cardiovascular protective, anti-inflammatory, antioxidant, and immunomodulatory effects. Epimedin C is a primary bioactive constituent and is mandated as a reference standard for the qualitative and quantitative analysis of Herba Epimedii in the Vietnamese Pharmacopoeia V. Consequently, the development of a cost-effective, domestic Epimedin C reference standard is critical for the rigorous quality control of this botanical drug. In this study, 6.5 g of Epimedin C was isolated and purified from 5 kg of Herba Epimedii raw material. The structural integrity was confirmed via spectroscopic techniques (1H and 13C-NMR, IR) and HPLC-DAD profiling. The chromatographic purity was determined to be 98.2% using the area normalization method at a test concentration of 1.0 mg/mL, while the total volatile content was measured at 5.0% via Thermogravimetric Analysis (TGA). Finally, by applying the mass balance approach to account for all impurities, the label-assigned content for 125 vials of the Epimedin C reference standard was established as 93.3 ± 0.44% (k = 2).