Powdered Acacia-Gummi Arabicum Pulveratum

Powdered Acacia

Gummi Arabicum Pulveratum

Powdered Acacia is the powder of Acacia.

Description: 

Powdered Acacia occurs as a white to light yellowish white powder. It is odorless, tasteless, but produces a mucilaginous sensation on the tongue.
Under a microscope, Powdered Acacia, immersed in olive oil or liquid paraffin, reveals colorless, angular fragments or nearly globular grains. Usually starch grains or vegetable tissues are not observed or very trace, if any.
Powdered Acacia (1.0 g) dissolves almost completely in 2.0 mL of water, and the solution is acid.
It is practically insoluble in ethanol (95).

Identification: 

To 1 g of Powdered Acacia add 25 mL of water and 1 mL of sulfuric acid, and heat under a reflux condenser in a boiling water bath for 60 minutes. After cooling, add gently 2.0 g of anhydrous sodium carbonate. To 1 mL of this solution add 9 mL of methanol, mix well, centrifuge, and use the supernatant liquid as the sample solution. Separately, dissolve 10 mg of D-galactose in 1 mL water, add methanol to make 10 mL, and use this solution as the standard solution (1). Proceed with L-arabinose and with L-rhamnose monohydrate in the same manner as for the preparation of the standard solution (1), and use so obtained solutions as the standard solution (2) and the standard solution (3), respectively. Perform the test with these solutions as directed under Thin layer Chromatography. Spot 10 mL each of the sample solution and standard solutions (1), (2) and (3) on a plate of silica gel for thin-layer chromatography. Develop the plate with a mixture of acetone and water (9:1) to a distance of about 10 cm, and air-dry the plate. Spray evenly 1-naphthol-sulfuric acid TS on the plate, and heat at 105oC for 5 minutes: the three spots from the sample solution are the same with the spots of D-galactose, L-arabinose and L-rhamnose from the standard solution in the color tone and the Rf value, respectively.

Purity:

(1) Insoluble residue.To 5.0 g of Powdered Acacia add 100 mL of water and 10 mL of dilute hydrochloric acid, and dissolve by gentle boiling for 15 minutes with swirling. Filter the warm mixture through a tared glass filter (G3), wash the residue thoroughly with hot water, and dry at 105oC for 5 hours: the mass of the residue does not exceed 10.0 mg.
(2) Tannin-bearing gums.To 10 mL of a solution of Powdered Acacia (1 in 50) add 3 drops of iron (III) chloride TS: no dark green color is produced.
(3) Glucose.Dissolve 10 mg of glucose in 1 mL of water, add methanol to make 10 mL, and use this solution as the standard solution. Proceed with the sample solution obtained in the Identification and the standard solution obtained here as directed in the Identification: any spot at the Rf value corresponding to glucose from the standard solution does not appear from the sample solution.

Loss on drying:

Not more than 15.0z (6 hours).

Total ash:

Not more than 4.0z.

Acid-insoluble ash:

Not more than 0.5z.

Containers and storage:

Containers.Tight containers.

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