Ban Xia (Qing)

PINELLIAE RHIZOMA (半夏, Banxia) Pinellia Tuber The drug is collected in summer and autumn, washed clean, removed from the outer skin and fibrous roots, and dried in the sun. Description Subspheroidal, sometimes slightly oblique, 0.7–1.6 cm in diameter. Externally white or pale yellow. The apex bears a depressed stem scar, densely surrounded by pitted root scars. The base is obtuse, rounded, and relatively smooth. Texture hard. Fracture white and starchy. Odour slight. Taste pungent, producing a numbing and irritating sensation. Identification (1) Powder Almost white. Starch granules abundant. Simple granules subrounded, semicircular or rounded-polygonal, 2–20 μm in diameter. Hilum slit-shaped, V-shaped, or stellate. Compound granules composed of 2–6 components. Raphides of calcium oxalate embedded in elliptical mucilage cells or scattered freely. Needle crystals 20–144 μm long. Spiral vessels 10–24 μm in diameter. (2) To 1 g of the powder add 10 mL of methanol. Heat under reflux for 30 minutes. Filter. Concentrate the filtrate to about 0.5 mL as the test solution. Dissolve Arginine CRS, Alanine CRS, Valine CRS, and Leucine CRS in 70% methanol to prepare a mixed solution containing 1 mg of each per 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 (8:3:1) as the mobile phase. Apply separately 5 μL of the test solution and 1 μL of the reference solution to the plate. After development, remove the plate, dry in air, spray with Ninhydrin TS, and heat at 105°C until the bands become distinct. The bands in the chromatogram obtained with the test solution correspond in position and colour to those obtained with the reference solution. (3) To 1 g of the powder add 10 mL of ethanol. Heat under reflux for 1 hour. Filter. Concentrate the filtrate to 0.5 mL as the test solution. Prepare a solution of 1 g of Pinelliae Rhizoma 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 a mixture of petroleum ether (60–90°C), ethyl acetate, acetone, and formic acid (30:6:4:0.5) as the mobile phase. Apply separately 5 μL of each solution to the plate. After development, remove the plate and dry in air. Spray with 10% sulfuric acid in ethanol. Heat at 105°C until the bands become distinct. The bands 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 13.0% (0832, Method 2). Total Ash Not more than 4.0% (2302). Extractives Carry out the method for determination of water-soluble extractives (2201, Cold Maceration Method). Not less than 7.5%. Prepared Slices Processing Pinelliae Rhizoma (Unprocessed) Break into pieces before use. Description As required for the crude drug. Identification As required for the crude drug. Water, Total Ash, and Extractives As required for the crude drug. Property and Flavor Warm; pungent; toxic. Meridian Tropism Spleen, Stomach, and Lung meridians. Actions To dry dampness, resolve phlegm, redirect rebellious qi downward, stop vomiting, disperse focal distention, and dissipate nodules. Indications Damp-phlegm, cold-phlegm, cough, wheezing, profuse sputum, dizziness and palpitations due to retention of phlegm-fluid, dizziness due to wind-phlegm, phlegm syncope, headache, vomiting, regurgitation, fullness and oppression of the chest and epigastrium, and plum-pit qi. For external use: abscesses, swellings, and phlegm nodules. Administration and Dosage Generally processed products should be used for oral administration. 3–9 g. For external use, an appropriate amount may be ground into juice or powder, mixed with liquor, and applied to the affected area. Precautions and Warnings Incompatible with: Aconiti Radix Aconiti Radix Cocta Aconiti Kusnezoffii Radix Aconiti Kusnezoffii Radix Cocta Aconiti Radix Lateralis Praeparata The unprocessed drug should be used with caution for oral administration. Storage Preserve in a well-ventilated and dry place, protected from insects.