Morphine

MORPHINE

Morphine is the most important alkaloid of opium, Papaver somniferum Family-Papaveraceae). A good grade of pium contains about 10 per cent of morphine. Most of the morphine in opium is present as sulphate or in combination meconic acid.

For the extraction of morphine, the powdered opium is ixed with calcium chloride solution which reacts with the alkaloidal salt by double decomposition, precipitating calcium meconate and calcium sulphate and leaving the alkaloids in solution as hydrochlorides.

After addition of hot water, the liquid is filtered and sodium sulphate is added to the filtrate to prevent oxidation of the morphine. The liquid is concentrated by evaporation, and sodium acetate is added to precipitate narcotine and other alkoloids. which are separated. The morphine is precipitated by the addition of calcium hydroxide and ammonium chloride, which interact with liberation of free ammonia. Addition of small amount of alcohol helps to induce crystallization of the morphine. Codeine remains in the filtrate. The morphine is purified by ashing it with benzene or by recrystallizing its hydrochloride salt.

Morphine, m.p. 254 (decomp.), is a colourless, crystalline compound, very sparingly soluble in water and ether; slightly soluble in ammonia, benzene, alcohol and chloroform; highly soluble in methanol; freely soluble in solutions of fixed alkali and alkaline earth hydroxides, in phenol and cresols. It has an intensely bitter taste. It is a monoacid tertiary base, forming salts with one equivalent of an acid. It has phenolic and basic properties. When morphine is heated with zinc dust, it is decomposed with formation of simpler compounds like pyridine and quinoline .

Tests for Morphine:

1.     Morphine is soluble in aqueous sodium hydroxide. Solutions of morphine salt are precipitated on addition of ammonia to form free base which is dissolved on addition of sodium hydroxide.

2.      Morphine liberates iodine from iodic acid.

3.       When a dilute solution of a morphine salt, acidified with sulphuric acid, is added to a solution of potassium iodate

4.      containing starch mucilage, a deep blue colour is formed

5.      Addition of a drop of ferric chloride to a solution of morphine salt produces bluish-green colour

6.      Morphine (0.1 g) is heated with concentrated sulp acid on a water bath for 15 minutes and the cold sol is treated with a few drops of dilute nitric acid, a blood colour is formed.

Morphine hydrochloride, m.p. 200 (decomp.), is prepa by neutralizing a hot aqueous suspension of morphine will dilute hydrochloric acid and then concentrating the resulti solution by evaporation to get crystals.

It occurs as colourless, silky, glistering crystals or wh crystalline powder. It is soluble in water, glycerine and boili alcohol; practically insoluble in ether or chloroform. Solution have a pH of about 5 and may be sterilized by boiling. It protected from light and kept in well-closed containers.

Morphine Sulphate (Brand Name : MST-1 continus). m.p. 250 (decomp). is prepared in the same manner as the hydrochlori It occurs as white. odourless. acicular crystals, cubical masses or crystalline powder. It loses water of crystallization at room temperature and darkens on exposure to light. It is soluble water (l in 21), alcohol (1 in 1000); insoluble in chloroform a ether; pH of aqueous solutions is about 4.8. Ampuled aqueous solutions of morphine sulphate turn brown on storage. No los of analgesic potency and no increase in toxicity have ever been demonstrated for such discoloured solutions. It is protected from light and kept in airtight containers.

Uses : Morphine is a narcotic analgesic agent used for the symptomatic relief of pain, to alleviate the anxiety associated with pain; as general anaesthetic in high doses.

Side Effect

The common side effects of morphine are nausea, vomiting constipation, drowsiness, and confusion. Dry mouth, sweating. facial flushing, vertigo, bradycardia, palpitation, orthostatic hypotension, hypothermia, restlessness, changes in mood and miosis also occur. Abuse leads to habituation or addiction.