Cang Er Zi

XANTHII FRUCTUS (苍耳子, Cang'erzi) Siberian Cocklebur Fruit (Fam. Compositae) The drug is collected in autumn when ripe, dried, and freed from the stalks, leaves, and other foreign matter. Description Fusiform or ovoid, 1–1.5 cm long and 0.4–0.7 cm in diameter. Externally yellowish-brown or yellowish-green, densely covered with hooked spines. The apex bears two relatively thick spines, either separated or united. The base has a fruit stalk scar. Texture hard but flexible. The transverse section shows a septum with two locules, each containing one achene. The achene is slightly fusiform, somewhat flattened on one side, with the persistent style remaining at the apex. Pericarp thin, greyish-black, with longitudinal wrinkles. Testa membranous, pale grey. Cotyledons two, rich in oil. Odour slight; taste slightly bitter. Identification (1) Powder Pale yellowish-brown to pale yellowish-green. Involucre fibres occur in bundles, arranged in a crisscross pattern. Epidermal cells of the pericarp are brown, subrectangular, and often connected with the fibres beneath. Pericarp fibres occur singly or in bundles, slender and fusiform, with pits and pit canals distinct or indistinct. Cells of the testa are pale yellow; the outer cells are subpolygonal with slightly thickened walls, while the inner cells possess papillae. Wood parenchyma cells are subrectangular with pitted walls. Cotyledon cells contain aleurone grains and oil droplets. (2) To 2 g of the powder add 25 mL of methanol, heat under reflux for 20 minutes, and filter. Concentrate the filtrate to about 2 mL as the test solution. Prepare a solution of 2 g of Xanthii Fructus Reference Drug in the same manner as the reference drug solution. Carry out the method for Thin-Layer Chromatography (0502), using silica gel G as the coating substance and the upper layer of a mixture of n-butanol, glacial acetic acid, and water (4:1:5) as the mobile phase. Apply separately 4 μL of each of the above two solutions to the plate. After development, remove the plate, dry it in air, and expose it to ammonia vapour until the spots become distinct. The spots in the chromatogram obtained with the test solution correspond in position and colour to those obtained with the reference drug solution. Water Not more than 12.0% (0832, Method 2). Total Ash Not more than 5.0% (2302). 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 acetonitrile and 0.4% phosphoric acid solution (10:90) as the mobile phase. Detection wavelength: 327 nm. The number of theoretical plates shall not be less than 3000, calculated with reference to the chlorogenic acid peak. Reference solution Accurately weigh an appropriate quantity of Chlorogenic Acid CRS. Dissolve in 50% methanol to produce a solution containing 50 μg/mL. Keep the solution below 10°C. Test solution Accurately weigh 0.5 g of the powder (through No. 3 sieve) into a stoppered conical flask. Add accurately 20 mL of 5% formic acid in 50% methanol, stopper, and weigh. Ultrasonicate (power 300 W, frequency 40 kHz) for 40 minutes. Cool and weigh again. Replenish any loss in weight with 5% formic acid in 50% methanol. Mix well and filter. Use the subsequent filtrate as the test solution. Procedure Inject accurately 5 μL of each of the reference solution and the test solution into the chromatograph. Determine and calculate the content. The drug contains not less than 0.25% of chlorogenic acid (C₁₆H₁₈O₉), calculated with reference to the dried drug. Prepared Slices Processing Xanthii Fructus Remove foreign matter. Description As required for the crude drug. Identification As required for the crude drug. Water As required for the crude drug. Total Ash As required for the crude drug. Assay As required for the crude drug. Xanthii Fructus (Stir-baked) Stir-bake the clean Xanthii Fructus according to the method for simple stir-baking (0213) until yellowish-brown. Remove the spines and sift clean. Description Similar in shape to the crude drug. Externally yellowish-brown with numerous spine scars. Odour slightly aromatic. Identification As required for the crude drug. Water Not more than 10.0%, following the method for the crude drug. Total Ash As required for the crude drug. Property and Flavor Warm; pungent and bitter; toxic. Meridian Tropism Lung meridian. Actions Disperse wind-cold, relieve nasal obstruction, and dispel wind-dampness. Indications Wind-cold headache, nasal obstruction with rhinorrhea, allergic rhinitis, sinusitis, pruritus due to rubella, and painful fixed Bi syndrome with muscular spasm. Administration and Dosage 3–10 g. Storage Preserve in a dry place.