Ban Lan Gen

ISATIDIS RADIX (板蓝根, Banlangen) Isatis Root The drug is collected in autumn, removed from the soil, and dried in the sun. Description Cylindrical, slightly tortuous, 10–20 cm long and 0.5–1 cm in diameter. Externally greyish-yellow or brownish-yellow, with longitudinal wrinkles and transverse lenticels, bearing rootlets or rootlet scars. Rootstock slightly enlarged, showing dark green or dark brown petiole bases arranged in whorls and dense tubercles. Texture compact and firm. Fracture yellowish-white in the bark and yellow in the wood. Odour slight. Taste initially sweetish, then bitter and astringent. Identification (1) Transverse section Cork consists of several layers of cells. Phelloderm narrow. Phloem broad with distinct medullary rays. Cambium forms a continuous ring. Xylem vessels yellow, subrounded, up to 80 μm in diameter. Xylem fibres occur in bundles. Parenchymatous cells contain abundant starch granules. (2) To 0.5 g of the powder add 20 mL of dilute ethanol. Ultrasonicate for 20 minutes. Filter. Evaporate the filtrate to dryness. Dissolve the residue in 1 mL of dilute ethanol as the test solution. Prepare a solution of 0.5 g of Isatidis Radix Reference Drug in the same manner as the reference drug solution. Dissolve Arginine CRS in dilute ethanol to prepare a solution containing 0.5 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 n-butanol, glacial acetic acid, and water (9:5:5) as the mobile phase. Apply separately 1–2 μL of each solution to the plate. After development, remove the plate, dry with a stream of hot air, spray with Ninhydrin TS, and heat at 105°C 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 and the reference solution. (3) To 1 g of the powder add 20 mL of 80% methanol. Ultrasonicate for 30 minutes. Filter. Evaporate the filtrate to dryness. Dissolve the residue in 1 mL of methanol as the test solution. Prepare a solution of 1 g of Isatidis Radix Reference Drug in the same manner as the reference drug solution. Dissolve (R,S)-Epigoitrin CRS in methanol to prepare a solution containing 0.5 mg/mL as the reference solution. Carry out the method for Thin-Layer Chromatography (0502) using silica gel GF254 as the coating substance and a mixture of petroleum ether (50–90°C) and ethyl acetate (1:1) as the mobile phase. Apply separately 5–10 μL of each solution to the plate. After development, remove the plate and dry in air. Examine under ultraviolet light (254 nm). The spots in the chromatogram obtained with the test solution correspond in position and colour to those obtained with the reference drug solution and the reference solution. Water Not more than 15.0% (0832, Method 2). Total Ash Not more than 9.0% (2302). Acid-insoluble Ash Not more than 2.0% (2302). Extractives Carry out the method for determination of ethanol-soluble extractives (2201, Hot Extraction Method) using 45% ethanol as the solvent. Not less than 25.0%. 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 : 0.02% phosphoric acid = 7 : 93 Detection wavelength: 245 nm The number of theoretical plates shall be not less than 5000, calculated with reference to the (R,S)-epigoitrin peak. Reference solution Accurately weigh (R,S)-Epigoitrin CRS. Dissolve in methanol to prepare a solution containing 40 μg/mL. Test solution Accurately weigh 1 g of the powder (through No. 4 sieve) into a stoppered conical flask. Add accurately 50 mL of water. Weigh. Decoct for 2 hours. Cool and weigh again. Replace any loss in weight with water. Mix well and filter. Use the subsequent filtrate as the test solution. Procedure Inject accurately 10–20 μL of the reference solution and the test solution into the chromatograph. Determine and calculate the content. The drug contains not less than 0.020% of (R,S)-epigoitrin (C₅H₈NOS), calculated with reference to the dried drug. Prepared Slices Processing Remove foreign matter. Wash clean. Soften thoroughly. Cut into thick slices. Dry. Description Rounded thick slices. Outer surface pale greyish-yellow to pale brownish-yellow, with longitudinal wrinkles. Cut surface yellowish-white in the bark and yellow in the wood. Odour slight. Taste initially sweetish, then bitter and astringent. Identification As required for the crude drug, except for the transverse section. Water Not more than 13.0%, following the method for the crude drug. Total Ash Not more than 8.0%, following the method for the crude drug. Acid-insoluble Ash and Extractives As required for the crude drug. Assay Contains not less than 0.030% of (R,S)-epigoitrin (C₅H₈NOS), following the method for the crude drug. Property and Flavor Cold; bitter. Meridian Tropism Heart and Stomach meridians. Actions To clear heat, remove toxins, cool the blood, and benefit the throat. Indications Epidemic febrile diseases, seasonal epidemic toxins, fever with sore throat, macular and papular eruptions due to warm toxins, mumps, scarlet fever, facial erysipelas, erysipelas, and carbuncles or abscesses. Administration and Dosage 9–15 g. Storage Preserve in a dry place, protected from mould and insects.