Bai Xuan Pi (Bai Xian Pi)

DICTAMNI CORTEX (白鲜皮, Baixianpi) Densefruit Pittany Root Bark The drug is collected in spring and autumn. The roots are excavated, soil and rough outer bark are removed, the root bark is stripped off, and dried. Description Quilled, 5–15 cm long, 1–2 cm in diameter, and 2–5 mm thick. Outer surface greyish-white or pale greyish-yellow, with fine longitudinal wrinkles and rootlet scars, frequently bearing small protruding granular dots. Inner surface whitish, with fine longitudinal striations. Texture fragile, dusty on breaking. Fracture uneven and somewhat lamellar. When the outer layer is peeled off, numerous glittering small spots are visible under reflected light. Odour mutton-like; taste slightly bitter. Identification (1) Transverse section Cork consists of 10 or more layers of cells. Phelloderm narrow. Fibres mostly scattered singly, yellow, 25–100 μm in diameter, with thickened and distinctly striated walls. Phloem broad. Medullary rays 1–3 cells wide. Fibres scattered singly throughout the phloem. Parenchymatous cells contain abundant clusters of calcium oxalate, 5–30 μm in diameter. (2) To 1 g of the powder add 20 mL of methanol. Ultrasonicate for 30 minutes and filter. Evaporate the filtrate to dryness. Dissolve the residue in 1 mL of methanol as the test solution. Dissolve Obacunone CRS and Fraxinellone CRS in methanol to prepare a mixed solution containing 1 mg of each per mL as the reference solution. Carry out the method for Thin-Layer Chromatography (0502), using silica gel G as the coating substance and a mixture of toluene, cyclohexane, and ethyl acetate (3:3:3) as the mobile phase. Apply separately 5 μL of each solution to the plate. After development, remove the plate and dry in air. Spray with 5% vanillin in sulfuric acid solution, then heat at 105°C until the spots become clearly visible. The spots in the chromatogram obtained with the test solution correspond in position and colour to those obtained with the reference solution. Water Not more than 14.0% (0832, Method 2). Extractives Carry out the method for determination of water-soluble extractives (2201, Cold Maceration Method). Not less than 20.0%. Assay Carry out the method for High-Performance Liquid Chromatography (0512). Chromatographic system and system suitability Use octadecylsilane-bonded silica gel as the stationary phase. Use a mixture of methanol and water (60:40) as the mobile phase. Detection wavelength: 236 nm. The number of theoretical plates shall be not less than 3000, calculated with reference to the fraxinellone peak. Reference solutions Accurately weigh appropriate quantities of Fraxinellone CRS and Obacunone CRS separately. Dissolve each in methanol to prepare solutions containing: Fraxinellone: 60 μg/mL Obacunone: 0.1 mg/mL Test solution Accurately weigh 1 g of the coarse powder (through No. 4 sieve) into a stoppered conical flask. Add accurately 25 mL of methanol and weigh. Heat under reflux for 1 hour. Cool and weigh again. Replace any loss of solvent with methanol. Mix well and filter. Use the subsequent filtrate as the test solution. Procedure Inject accurately 10 μL of each reference solution and the test solution into the chromatograph. Determine and calculate the contents. The drug contains not less than 0.050% of fraxinellone (C₁₄H₁₆O₃) and not less than 0.15% of obacunone (C₂₆H₃₀O₇), calculated with reference to the dried drug. Prepared Slices Processing Remove foreign matter. Wash clean. Soften briefly. Cut into thick slices. Dry. Description In irregular thick slices. Outer surface greyish-white or pale greyish-yellow, with fine longitudinal wrinkles and rootlet scars, often bearing small protruding granular dots. Inner surface whitish, with fine longitudinal wrinkles. Cut surface whitish and somewhat lamellar. Odour mutton-like. Taste slightly bitter. Identification As required for the crude drug, except for the transverse section. Water As required for the crude drug. Extractives As required for the crude drug. Assay As required for the crude drug. Property and Flavor Cold; bitter. Meridian Tropism Spleen, Stomach, and Bladder meridians. Actions To clear heat, dry dampness, dispel wind, and remove toxins. Indications Dampness-heat sores and skin infections with yellow purulent discharge, eczema, rubella, scabies, tinea, wind-dampness-heat Bi syndrome, jaundice, and dark-colored urine. Administration and Dosage 5–10 g. For external use, an appropriate amount may be decocted for bathing or ground into a fine powder for application to the pars affecta (affected area). Storage Preserve in a well-ventilated and dry place.