Zentiva, A.s.

Saneca Pharmaceuticals A.s.

Richard Hercek

Bohumil Proksa

Dusan Vandák

Ján Gaspar

Miroslav Kavala

Miroslav Palík

Alojz Skoda

The invention describes a method for purification of naltrexone base from reaction mixtures concentrated by evaporation and/or from mixtures containing naltrexone in the presence of other organic or inorganic substances by trituration and/or extraction and crystallization from cyclopentyl methyl ether (CPME), optionally from a mixture of cyclopentyl methyl ether and another organic solvent. Naltrexone of high purity is obtained by this method and can be used in a parenteral dosage form.

Method for isolation and purification of naltrexone

The invention solves a new method of preparation of Carvedilol for pharmaceutical use. In the synthesis of Carvedilol a reaction of 4-(oxirane-2-ylmethoxy)-9H-arbazole (II) with 2-(2-methoxyphenoxy)ethylamine salts (IV) in the presence of a base, in an alcohol having the number of carbons C2 to C5 as a solvent, at an elevated temperature, is used. After processing of the crude reaction mixture crude Carvedilol is obtained, which is purified by crystallization from ethylacetate with an addition of activated carbon and the final substance is formulated by crystallization from ethylacetate.

Process for preparation of carvedilol

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Hlohovec, Slovakia

Richard Hercek