Alkaloids: Opium (Afim- अफ़ीम) - Pharmacognosy B Pharmacy 5th Semester

Opium (or poppy tears), narcotic drug is dried latex obtained obtained from the unripe seedpods of the opium poppy, Papaver somniferum.

Opium Poppy Seed Pod execuding Latex

Synonyms:

• Crude Opium,
• Raw Opium,
• Gum Opium,
• Afim, Aphim (अफ़ीम) - Hindi,

Biological Source:

Opium is the air dried milky latex obtained by incision from the unripe capsules of Papaver somniferum Linn, or its variety P. album Decand.

Family - Papaveraceae.

Geographical Source:

It is mainly found in Turkey, Russia, Yugoslavia, Tasmania, India, Pakistan, Iran, Afghanistan, China, Burma, Thailand and Laos. In India, Opium is cultivated in M.P. (Neemuch) and U.P. for alkaloidal extraction and seed production.

History:

The cultivation of opium dates back to 3400 B.C. in Mesopotamia and by 1300 B.C. Egyptians began the cultivation of opium thebaicum. Hippocrates ‘the father of medicine’, (460–357 B.C.) prescribed drinking the juice of the white poppy mixed with the seed of nettle and also acknowledged its use as narcotic and styptic in internal diseases. It was Alexander the Great, who introduced opium to India and Persia. During the 17th century tobacco smoking was introduced in China, which resulted in its extensive. In 1800 control on opium supply and prices was brought and in 1805 Friedrich W. Seiturner (German pharmacist) isolated and identified the chief chemical constituent of opium. The compound isolated was named morphium (morphine) after Morpheus, the god of dreams. Eventually many other constituents like codeine (1832) and papaverine (1848) were also isolated and identified. Due to the uncontrolled use of opium in china (late 18th century) the imperial court had to ban its use. The United States in 19th century made easy availability of the opium preparations and the ‘patent medicines’. Later on during the war, the Union Army were provided with enough amount of opium pills, laudanum, morphine sulphate, etc., which made opium addiction known as the ‘army disease or the ‘soldier’s disease’.

By 1870s, substitute for morphine by acetylating morphine were prepared and in 1898 a German company manufactured 3, 6-diacetylmorphine (Heroin) in bulk quantity. In December 1914, Harrison Narcotics Act which called for control of each phase of the preparation and distribution of medicinal opium, morphine, heroin, cocaine, and any new derivative with similar properties, was enforced by the United States Congress. The Federal Controlled Substances Act of 1970 is the redefined act of the Harrison Act. In 1999, opium was declared as the Bumper crop of Afghanistan by producing 75% of world’s heroin. In December 2002 the U.K. government under the health plan, will make heroin available free on National Health Service to all those with a clinical need for it.

Morphology/Macroscopics Characters:

Opium occurs in rounded or flattened mass which is 8–15 cm in diameter and weighing from 300 g to 2 g each. The external surface is pale or chocolate-brown, texture is uniform and slightly granular. It is plastic like when fresh and turns hard and brittle after sometime. Fragment of poppy leaves are present on the upper surface. Internal surface is coarsely granular, reddish-brown, lustrous; odour is characteristic; taste is bitter and distinct. Opium is intended only as a starting material for the manufacture of galenical preparations and is not dispensed as such.

Chemical Constituents:

Opium contains about 35 alkaloids among which morphine (10–16%) is the most important base. The alkaloids are combined with meconic acid. The other alkaloids isolated from the drug are codeine (0.8–2.5%), narcotine, the-baine (0.5–2%). noscapine (4–8%), narceine and papaverine (0.5–2.5%). Morphine contains a phenanthrene nucleus. The different types of alkaloids isolated are:

• Morphine Type: Morphine, codeine, neopine, pseudo or oxymorphine, thebaine and porphyroxine. Morphine consists of alkaloids which has phenanthrene nucleus whereas those of the papaverine group has benzyliso-quinoline structure. Protopine and hydrocotamine are of different structural types. The morphine molecule has both a phenolic and an alcoholic hydroxyl group and acetylated form is diacetyl morphine or heroin. Codeine is ether of morphine (methyl-morphine). Other morphine ethers which are used medicinally are ethylmorphine and pholcodine.
• Phthalide Isoquinoline Type: Hydrocotarnme, narcotoline, 1-narcotine, noscapine, oxynarcotine, narceine, and 5’-O-demethyl-narcotine.
• Benzyl Isoquinoline Type: Papaverine, dl-laudanine, lau-danidine, codamine and laudanosine.
• Cryptopine Type: Protopine, cryptopine.
• Unknown Constituents: Aporeine, diodeadine, meconidine, papaveramine and lanthopine.

The drug also contains sugars, sulphates, albuminous compounds, colouring matter and moisture. In addition to these anisaldehyde, vanillin, vanillic acid, β-hydroxystyrene, fumaric acid, lactic acid, benzyl alcohol, 2-hydroxycinchonic acid, phthalic acid, hemipinic acid, meconin and an odorous compound have also been reported.

Chemical Tests:

• Aqueous extract of Opium with FeCl3 solution gives deep reddish purple colour which persists 
  on addition of HCl. It indicates the presence of meconic acid.
• Morphine gives dark violet colour with conc. H2SO4 and formaldehyde.

Uses:

• Opium and morphine have narcotic, analgesic and sedative action and used to relieve pain, diarrhoea dysentery and cough.
• Poppy capsules are astringent, somniferous, soporific, sedative and narcotic and used as anodyne and emollient. 
• Codeine is mild sedative and is employed in cough mixtures. 
• Noscapine is not narcotic and has cough suppressant action acting as a central antitussive drug. 
• Papaverine has smooth muscle relaxant action and is used to cure muscle spasms. 
• Opium, morphine and the diacetyl derivative heroin, cause drug addiction.