Crystalline modification of the hydrogen chloride of the 2-dimethylamino ethyl ester of n-butylamino benzoic acid, process for making this modification and medicinal product for anaesthesia of the eyes on your basis

摘要

A new crystalline modification of hydrochloride of 2-dimethylaminoethyl ether of n-butylamino benzoic acid is characterized by one endothermic melting effect at a temperature of 148.6 DEG +/- 0.3 DEG C and by the values of the interplane distances d and of relative intensities of reflexes (I). A method of obtaining said substance consists in that the solution of hydrochloride of 2-dimethylaminoethyl ether of n-butylamino benzoic acid of polymorphic form in the water or in an organic solvent or in their mixture is cooled by means of a cooling agent at a speed no less than 8 DEG C/min up to its full crystallization with subsequent drying of the thus obtained crystals. The claimed substance has local anesthesia properties and is an active agent of a pharmaceutical preparation for anesthesia of the eye (the content of the active substance from 0.05 to 0.5 percent by weight).