Baical Skullcap Root
Baical Skullcap Root is the dried root of Scutellaria baicalensis Georgi (Fam. Labiatae). The drug is collected in spring and autumn, removed from rootlet and soil, dashed to peel the rugged outer bark after being sun-dried, and then dried thoroughly.
Description: Conical, twisted, 8-25 cm long, 1-3 cm in diameter. Externally brownish-yellow or dark yellow, bearing sparse warty traces of rootlets, the upper part rough, with twisted longitudinal wrinkles or irregular reticula, the lower part with longitudinal striations and fine wrinkles. Texture hard and fragile, easily broken, fracture yellow, reddish-brown in the centre; the central part of an old root dark brown or brownish-black, withered or hollowed. Odour, slight, taste, bitter.
Identification: (1) Powder: Yellow. Phloem fibres scattered singly or in bundles, fusiform, 60-250 mm long, 9-33 mm in diameter, thick-walled, with fine pit-canals. Stone cells subrounded, subsquare or rectangular, relatively thick-walled or heavily thick-walled. Cork cells brownish-yellow, polygonal. Reticulated vessels numerous, 24-72 mm in diameter. Wood fibres frequently broken, about 12 mm in diameter, with oblique pits. Starch granules abundant, simple granules spheroidal, 2-10 mm in diameter, hilum distinct, compound granules composed of 2-3 components.
(2) To 1 g of the powder, add 20 ml of methanol, ultrasonicate for 20 minutes, filter and evaporate the filtrate to dryness. Dissolve the residue in 1 ml of methanol as the test solution. Produce a the reference drug solution of 1 g of Radix Scutellariae reference drug in the same manner. Dissolve a quantity of baicalin CRS in methanol to produce a solution containing 1 mg per ml as the reference solution. Carry out the method for thin layer chromatography (Appendix VI B), using silica gel G containing sodium carboxymethylcellulose and prepared with 4% sodium acetate as the coating substance and a mixture of ethyl acetate-butanone-formic acid-water (5:3:1:1) as the mobile phase. Apply separately to the plate 5 ml of each of the three solutions. After developing in a chamber pre-equilibrated with the mobile phase for 30 minutes and removal of the plate, dry it in air, spray with a 1% solution of ferric chloroform in ethanol. The spots in the chromatogram obtained with the test solution correspond in position and colour to the spots in the chromatogram obtained with the reference drug solution and a dark-green spot in the chromatogram obtained with the test solution corresponds in position and color to the spot in the chromatogram obtained with the reference solution.
Total ash : Not more than 6.0% (Appendix IX K).
Assay: Carry out the method for high performance liquid chromatography (Appendix VI D).
Chromatographic system and system suitability: Use octadecylsilane bonded silica gel as the stationary phase and methanol-water-phosphoric acid (47:53:0.2) as the mobile phase. The wavelength of the detector is 280 nm. The number of theoretical plates of the column is not less than 2 500, calculated with the reference to the peak of baicalin.
Preparation of reference solution: Weigh accurately a quantity of baicalin CRS, dried in vaccum at 60oC for 4 hours, dissolve in methanol to produce a solution containing 60 mg per ml as the reference solution.
Preparation of test solution: Weigh accurately 0.3 g of medium powder [perform a determination of water (Appendix IX H, method 1)], add 40 ml of 70% ethanol, heat under reflux on a water bath for 3 hours, cool, and filter. Transfer the filtrate to a 100 ml volumetric flask, wash both the container and the residue for several times with a small volume of 70% ethanol, and filter the washings into the same flask. Dilute with 70% ethanol to volume, and mix well. Accurately measure 1 ml in a 10 ml volumetric flask, dilute with methanol to volume, and mix well.
Procedures: Accurately inject 10 ml of each of the reference solution and the test solution, respectively, into the column, determine and calculate the content. It contains not less than 9.0% of baicalin (C21H18O11) on the dried basis.
Processing: Radix Scutellariae Eliminate foreign matter, boil for 10 minutes, take out, soften thoroughly, or steam for half an hour, take out, then cut into thin slices and dry, protecting from exposure to strong sunlight.
Occurring in subrounded or irregular thin slices; externally yellowish-brown to brown; cut surface yellowish-brown or yellowish-green, striated radially. Carry out the methods as described under Identification test (1) and (2), show the same results. Carry out the method as described under Assay mentioned above, it contains not less than 8.0% of baicalin (C21H18O11).
Radix Scutellariae (processed with wine): Stir-bake the slices of Radix Scutellariae as described under the method for stir-baking with wine (Appendix II D) to dryness.
Occurring in subrounded or irregular thin slices; externally brown; cut surface yellowish-brown, striated radially, showing less burnt patches, sometimes appearing brown in the centre.
Carry out the method according to Assay mentioned above, not less than 8.0% of baicalin (C21H18O11).
Action: To remove damp-heat, to quench fire and counteract toxicity, to arrest bleeding, and to prevent abortion.
Indications: Discomfort in the chest, nausea and vomiting in eidemic febrile diseases caused by damp-heat or summer-heat; feeling of stuffiness in the abdomen, acute dysentery or jaundice caused by damp-heat; cough due to heat in the lung; high fever with dire thirst; spitting of blood and epistaxis due to heat in blood; carbuncles and sores; threatened abortion.
Usage and dosage: 3-9 g.
Storage: Preserve in a ventilated dry place, protected from moisture.