Chi Shao

PAEONIAE RADIX RUBRA (赤芍, Chishao) Red Peony Root Paeonia lactiflora Pall. or Paeonia veitchii Lynch (Fam. Ranunculaceae). The drug is collected in spring or autumn, removed from the rhizome and rootlets, and dried in the sun. Description Cylindrical, slightly curved, 5–40 cm long and 0.5–3 cm in diameter. Externally brown, rough, with longitudinal furrows and wrinkles, rootlet scars, and elongated transverse lenticel-like protuberances. The outer bark is sometimes easily exfoliated. Texture hard and brittle, easily broken. Fracture chalky white or pink. Bark narrow. Wood showing distinct radial striations, sometimes with clefts. Odour slight. Taste slightly bitter, sour, and astringent. Identification (1) Transverse section Cork consisting of several layers of brown cells. Cortical parenchymatous cells elongated tangentially. Phloem relatively narrow. Cambium forming a continuous ring. Xylem rays relatively broad. Vessels arranged radially and accompanied by wood fibres. Parenchymatous cells containing abundant starch granules and clusters of calcium oxalate. (2) To 0.5 g of the powder add 10 mL of ethanol. Shake thoroughly for 5 minutes. Filter. Evaporate the filtrate to dryness. Dissolve the residue in 2 mL of ethanol as the test solution. Dissolve Paeoniflorin CRS in ethanol to prepare a solution containing 2 mg/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 chloroform, ethyl acetate, methanol, and formic acid (40:5:10:0.2) as the mobile phase. Apply separately 4 μL of each solution to the plate. After development, remove the plate and dry in air. Spray with 5% vanillin in sulfuric acid. Heat until the spots become distinct. The blue-purple spot obtained with the test solution corresponds in position and colour to that obtained with the reference solution. 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. Mobile phase: Methanol : 0.05 mol/L potassium dihydrogen phosphate = 40 : 65 Detection wavelength: 230 nm The number of theoretical plates shall be not less than 3000, calculated with reference to the paeoniflorin peak. Reference solution Accurately weigh Paeoniflorin CRS, previously dried over phosphorus pentoxide under reduced pressure for 36 hours. Dissolve in methanol to prepare a solution containing 0.5 mg/mL. Test solution Accurately weigh 0.5 g of the coarse powder into a stoppered conical flask. Accurately add 25 mL of methanol. Weigh. Macerate for 4 hours. Ultrasonicate for 20 minutes. Allow to cool. Weigh again. Replace any loss of solvent with methanol. Mix well. Filter. Use the filtrate as the test solution. Procedure Inject accurately 10 μL of the reference solution and the test solution into the chromatograph. Determine and calculate the content. The drug contains not less than 1.8% of paeoniflorin (C₂₃H₂₈O₁₁), calculated with reference to the dried drug. Prepared Slices Processing Remove foreign matter. Grade according to size. Wash clean. Soften thoroughly. Cut into thick slices. Dry. Description Subrounded thick slices. Outer edge brown. Cut surface yellowish-white or pink. Bark narrow. Wood showing distinct radial striations, sometimes with clefts. Identification As required for the crude drug. Assay Contains not less than 1.5% of paeoniflorin (C₂₃H₂₈O₁₁), following the method for the crude drug. Property and Flavor Mildly cold; bitter. Meridian Tropism Liver meridian. Actions To clear heat, cool the blood, remove blood stasis, and relieve pain. Indications Heat entering the nutrient-blood level, macules and papules due to warm toxin, hematemesis, epistaxis, red and swollen painful eyes, hypochondriac pain due to liver qi stagnation, amenorrhea, dysmenorrhea, abdominal masses with pain, traumatic injuries, swelling, abscesses, sores, and ulcers. Administration and Dosage 6–12 g. Precautions and Warnings Incompatible with Veratri Nigri Radix et Rhizoma. Storage Preserve in a well-ventilated, dry place.