Artemisinin

C₁₅H₂₂O₅ 284.35

Chemical name (3R, 5aS, 6R, 8aS, 9R, 12S, 12aR)-Octahydro-3, 6, 9-trimethyl-3, 12-epoxy-12H-pyrano [4.3-j]-1, 2-benzodioxepin-10(3H)-one; CAS Reg. No. 63968 -64-9. Calculated with reference to the dried substance, Artemisinin contains not less than 99.0%

Characteristic Colorless needles or a white, crystalline powder; bitter in taste.

It is easy to solve in acetone, ethyl acetate, chloroform, benzene or glacial acetic acid and it is soluble in methanol, ethanol, diluted ethanol, aether and petroleum ether, and almost insoluble in water.
Melting range 150～153℃ (Appendix VIC of China Pharmacopoeia, Volume Two, 2000 Edition)
Specific optical rotation Weight appropriate amount of artemisinin accurately and add absolute ethyl-alcohol to make a solution containing 10mg of ART per ml, then measure it with the method described in Appendix VIE of China Pharmacopoeia, 2000 Edition. The specific rotation is ＋75°~＋78°.

Identification

(1) Add 0.5ml of absolute ethanol to dissolve about 5mg of the sample, mix 0.4ml of potassium iodide test solution and 2.5ml diluted sulfuric acid with 4 drops of starch indicator solution, then a violet color develops.

(2) Add 0.5ml of absolute ethanol to dissolve about 5mg of the sample, then add 0.5ml of hydroxylamine hydrochloride test solution and 0.25ml of sodium hydroxide solution. Boil it ratherish in a water bath and let it cool naturally. After adding 2 drops of hydrochloric acid and one drop of ferric chloride test solution to the solution, it will show dark mauve color immediately.

(3) The color and location of the principal spot of impurity in the chromatogram of test solution should be corresponding to that of ART control.

(4) The infrared absorption spectrum should be concordant with the reference spectrum of artemisinin.

Detection

(1) Related substances Add chloroform to the sample and control substance respectively to make a solution containing 10mg per ml. According the TLC method describing in the Appendix VB of China Pharmacopoeia, Volume Two, 2000 Edition, apply 3μl of each of the two solutions separately to one silica gel G coated plate, use petroleum ether (60-90℃)-aether (6:4) as developing agent, after developing, dry the plate in air and spray anisaldehyde-methanol solution (Add 10ml of glacial acetic acid and 5ml of oil of vitriol slowly to 55ml of methanol, cool it to room temperature, then add this solution to 30 ml of methanol containing 0.5ml of anisaldehyde, shake it to homogenize the solution and protected from light.) and then place it at 110℃ for 3-5 min, The color and location of the spot of impurity in the chromatogram of test solution should be corresponding to that of the control solution, no other spot of impurity in the chromatogram is showed.

(2) Loss on drying Dried to constant mass at 80℃, it loses not more than 0.5％.(Appendix Ⅷ N of China Pharmacopoeia)

(3) Residue of ignition It is not more than 0.1% of the original weight of tested sample. (Appendix Ⅷ N of China Pharmacopoeia)

Content measurement　

Weigh accurately appropriate amount of the sample, add ethanol to make a solution containing 50μg per ml. Accurately weigh 10ml of the test solution and control solution respectively to 50ml volumetric flasks and homogenize the solution. Add 0.2％ NaOH solution to dilute it to 50ml exactly and shake it to homogenize the solution, then place it in water bath at a constant temperature of 50±1℃ for 30 min, cool it to room temperature, treat 10ml ethanol with the same method as the blank solution, determine absorbance of the test solution at 292nm wave length according to method of Spectrophotometry (Appendix IV A, China pharmacopoeia).The assay of the artemisinin control is carried out with the same method.

Type: Antimalarial

Storage: Preserved in tightly closed containers and protected from light.