Acacia

Acacia
(Ph Eur monograph 0307)
Ph Eur
Definition
Acacia is the air-hardened, gummy exudate flowing naturally from or obtained by incision of the trunk and branches of Acacia senegal L. Willdenow and other species of Acacia of African origin.
Characters
Acacia is almost completely but very slowly soluble, after about 2 h, in twice its mass of water leaving only a very small residue of vegetable particles; the liquid obtained is colourless or yellowish, dense, viscous, adhesive, translucent and weakly acid to blue litmus paper. Acacia is practically insoluble in alcohol.
It has the macroscopic and microscopic characters described under identification tests A and B.
Identification
A. Acacia occurs as yellowish-white, yellow or pale amber, sometimes with a pinkish tint, friable, opaque, spheroidal, oval or reniform pieces (tears) of a diameter from about 1 cm to 3 cm, frequently with a cracked surface, easily broken into irregular, whitish or slightly yellowish angular fragments with conchoidal fracture and a glassy and transparent appearance. In the centre of an unbroken tear there is sometimes a small cavity.
B. Reduce to a powder (355). The powder is white or yellowish-white. Examine under a microscope using glycerolR (50 per cent V/V). The powder presents angular, irregular, colourless, transparent fragments. Only traces of starch or vegetable tissues are visible. No stratified membrane is apparent.
C. To 2 ml of solution S (see Tests) add 8 ml of waterR; the solution is laevorotatory.
D. Examine the chromatograms obtained in the test for glucose and fructose. The chromatogram obtained with the test solution shows three zones due to galactose, arabinose and rhamnose. No other important zones are visible, particularly in the upper part of the chromatogram.
E. Dissolve 1 g of the powdered drug (355) in 2 ml of waterR by stirring frequently for 2 h. Add 2 ml of alcoholR. After shaking, a white, gelatinous mucilage is formed which becomes fluid on adding 10 ml of waterR.
Tests
Solution S
Dissolve 3.0 g of the powdered drug (355) in 25 ml of waterR by stirring for 30 min. Allow to stand for 30 min and dilute to 30 ml with waterR.