สารบัญ

Thai name มดยอบ (MOT YOP)

Category  Astringent.

        Myrrh is an oleo-gum-resin obtained from the stem and branch of Commiphora myrrha (Nees) Engl. and possibly other species of Commiphora (Family Burseraceae).  It yields not less than 7.0 mL of volatile oil from each 100 g of drug.

Constituents   Myrrh contains a water-soluble gum, resins and volatile oil.  The major constituents of the oil are furanosesquiterpenes such as curzerene and furanodione.  It also contains monoterpenes, a-pinene and limonene.

Description  Odour, aromatic and characteristic; taste, bitter and acrid.

Macroscopical  Irregular or roundish grains or pieces, vary in size and shape, pale to dark orange-brown covered with  grey or yellowish brown dust.
Microscopical  Powdered drug of the oleo-gum-resin shows a few tissue fragments and substances from the plant including fragments of cork, stone cells, parenchyma, fibres, and calcium oxalate crystals.  Cork fragments reddish brown.  Stone cells polyhedral cells with partly or strongly thickened, pitted, lignified-walls, and with brownish content, occurring as solitary cells or arranged in group.  Parenchyma thin-walled.  Fibre sclerenchymatous.  Calcium oxalate crystals irregularly prismatic or polyhedral.

Other relevant information  The plant yielding myrrh is native to southern Arabia, northeastern Africa (mainly Somalia and Ethiopia) and southern Africa (e.g., Kenya).

Packaging and storage  Myrrh shall be stored in a cool and dry place.

Identification
     Triturate 400 mg of the crushed drug with 1 g of washed sand, shake for a few minutes with 10 mL of ether and filter.  Evaporate the filtrate to dryness in a porcelain dish, and add a few drops of nitric acid to the residue:  a purple-violet colour is produced immediately.
Transfer 100 mg of the powdered drug to a test-tube, and add 1 ml of nitric acid:  a red colour is produced.  Upon addition of a crystal of vanillin, the red colour deepens and does not diminish when water is added.
Carry out the test as described in the “Thin-Layer Chromatography” (Appendix 3.1).
     Standard solution  Dissolve 10 mg of thymol and 40 µL of anethole in 10 mL of ethanol.
     Test solution  To 200 mg of the powdered drug add 4 mL of ethanol, sonicate for 10 minutes and filter.
     Adsorbent  Silica gel F254 (HPTLC plate)
     Mobile phase  Glacial acetic acid, di-isopropyl ether, and cyclohexane (10:40:60).
     Application  Apply 5 µL each of Standard solution and Test solution as 8-mm bands.
     Development and drying  Allow the solvent front to ascend 6 cm above the line of application.  Dry the developed plate in air.
     Detection A  Examine the plate under ultraviolet light (366 nm).
     Results A  When examined under ultraviolet light (366 nm), the test solution shows no blue or violet fluorescent bands in the lower third of the chromatogram.
     Detection B  Spray the plate with anisaldehyde TS, heat at 100° for 2 minutes and examine under visible light.  Observe the result.
     Results B When examined under visible light, the standard solution shows a violet band due to anethole in the upper third and an orange band due to thymol around the middle of the chromatogram. The test solution shows a reddish violet band above the anethole band and a red band between the anethole and the thymol bands obtained from the standard solution; one violet and one brown bands appear in the lower third of the chromatogram.

Ethanol-insoluble matter   Not more than 75.0 per cent w/w, determined by the following method.  Transfer about 1 g, accurately weighed, to a suitable flask.  Add 30 mL of ethanol and shake vigorously for 10 minutes.  Filter the supernatant through a tared sintered-glass filter, avoiding the transfer of sediment from the flask.  Repeat the extraction with two 20-ml portions of ethanol.  Quantitatively transfer the sediment to the filter by rinsing the flask with ethanol.  Dry the residue at 105°
to constant weight.

Loss on drying  Not more than 15.0 per cent w/w after drying at 105° to constant weight (Appendix 4.15).

Total ash  Not more than 7.0 per cent w/w (Appendix 7.7).

Assay  Carry out the method for the “Determination of Volatile Oil” (Appendix 7.3), using 7 g, accurately weighed, in No. 710 powder.  Use 150 mL of water as the distillation liquid and a 500-mL round-bottomed flask.  Distil at the rate of 2 to 3 mL per minute for 4 hours. 
Use 0.5 mL of xylene in the graduated tube.