Ce Bai Ye(Tan)

PLATYCLADI CACUMEN (侧柏叶, Cebaiye) Chinese Arborvitae Twig and Leaf Platycladus orientalis (L.) Franco (Fam. Cupressaceae). The drug is collected in summer and autumn and dried in the shade. Description Frequently branched. Ultimate branchlets flattened. Leaves minute, scale-like, decussate, closely appressed to the branchlets, dark green or yellowish-green. Texture brittle and easily broken. Odour delicately aromatic. Taste bitter, astringent, and slightly pungent. Identification (1) Powder Yellowish-green. Upper epidermal cells of the leaves rectangular, with slightly thickened walls. Lower epidermal cells subsquare. Stomata numerous and sunken. Subsidiary cells relatively large, dumbbell-shaped in side view. Parenchymatous cells containing oil droplets. Fibres slender, approximately 18 μm in diameter. Bordered-pitted tracheids occasionally present. (2) Place 3 g of the powder into a Soxhlet extractor. Extract with ether under reflux until the extract becomes colourless. Discard the ether extract. Remove residual ether from the residue. Add 50 mL of 70% ethanol. Heat under reflux for 1 hour. Filter while hot. Evaporate the filtrate to dryness. Dissolve the residue in 25 mL of water. Add 3 mL hydrochloric acid solution. Heat for 30 minutes to hydrolyze. Cool immediately. Extract with ethyl acetate (20 mL × 2). Combine the ethyl acetate extracts. Wash with water (10 mL × 3). Discard the washings. Evaporate the ethyl acetate layer to dryness on a water bath. Dissolve the residue in 5 mL methanol as the test solution. Dissolve Quercetin CRS in ethanol to prepare a solution containing 0.1 mg/mL as the reference solution. Carry out the method for Thin-Layer Chromatography (0502) using high-performance silica gel G as the coating substance and a mixture of toluene : ethyl acetate : formic acid (5:2:1) as the mobile phase. Apply separately 3 μL of each solution. After development, dry in air. Spray with 1% aluminium chloride in ethanol. Examine under UV 365 nm. The fluorescent band obtained with the test solution corresponds in position and colour to that obtained with the reference solution. Foreign Matter Not more than 6.0% (2301). Water Not more than 11.0% (0832, Method 4). Total Ash Not more than 10.0% (2302). Acid-insoluble Ash Not more than 3.0% (2302). Extractives Carry out the method for determination of ethanol-soluble extractives (2201, Hot Extraction Method) using ethanol as the solvent. Not less than 15.0%. 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. Mobile phase: Methanol : 0.01 mol/L potassium dihydrogen phosphate : glacial acetic acid = 40 : 60 : 1.5 Detection wavelength: 254 nm The number of theoretical plates shall be not less than 1500, calculated with reference to the quercitroside peak. Reference solution Accurately weigh Quercitroside CRS. Dissolve in methanol to prepare a solution containing 50 μg/mL. Test solution Accurately weigh 0.5 g of the powder into a stoppered conical flask. Add accurately 20 mL of methanol. Weigh. Ultrasonicate for 30 minutes. Cool. Weigh again. Replace any loss in weight with methanol. Shake well. Filter. Use the subsequent 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 0.10% of quercitroside (C₂₁H₂₀O₁₂), calculated with reference to the dried drug. Prepared Slices Processing Platycladi Cacumen Remove coarse twigs and foreign matter. Description As required for the crude drug. Identification As required for the crude drug. Water and Extractives As required for the crude drug. Assay As required for the crude drug. Platycladi Cacumen (Carbonized) Carbonize Platycladi Cacumen according to the method for carbonizing by stir-baking (0213) until the surface becomes dark brown while the interior is yellowish-brown. Description Similar in shape to the crude drug. Leaves blackish-brown. Texture brittle and easily broken. Fracture brown. Odour aromatic. Taste slightly bitter and astringent. Identification As required for the crude drug. Property and Flavor Cold; bitter and astringent. Meridian Tropism Lung, Liver, and Spleen meridians. Actions To cool the blood, stop bleeding, resolve phlegm, relieve cough, promote hair growth, and darken the hair. Indications Hematemesis, epistaxis, hemoptysis, hematochezia, excessive uterine bleeding, prolonged spotting, cough due to lung heat, alopecia caused by blood heat, and premature greying of the hair. Administration and Dosage 6–12 g. For external use, apply an appropriate amount. Storage Preserve in a dry place.