A Validated Isocratic HPLC–UV Method for the Simultaneous Quantification of Corilagin and Geraniin in Geranium wilfordii Maxim. Extract

<i>Geranium wilfordii</i> Maxim. is a traditional medicinal plant rich in ellagitannins such as corilagin (CG) and geraniin (GR), which possess antioxidant and anti-inflammatory properties. However, accurate quantification of CG and GR in complex herbal matrices is hindered by co-eluting impurities and poor UV resolution. Here, we developed and validated a simple isocratic HPLC-UV method for their simultaneous determination in <i>G. wilfordii</i> extract. Separation was achieved on a Polaris 3 C18-A column (250 mm × 4.6 mm, 3 µm) using acetonitrile/0.2% formic acid in water (11:89, <i>v</i>/<i>v</i>) with UV detection at 270 nm. The method showed excellent linearity (25-300 µg/mL, R² > 0.995), precision (RSD < 2.7%), accuracy (recovery 99.5-101.2%), and low detection limits (<3 µg/mL). Previous approaches have relied on gradient HPLC or MS-based techniques, often requiring long run times, costly instrumentation, or additional purification (e.g., HSCCC). In contrast, this study demonstrates a validated isocratic method that enables baseline separation and simultaneous quantification of CG and GR in a single run. This robust and simplified analytical strategy provides a practical tool for routine quality control and phytochemical standardization, with potential applications across pharmaceutical, food, and cosmetic industries.