Non-solvated crystalline form "A" of 3-(4-cynnamyl-1-piperazinyl)iminomethylrifamycine SV and a method of its production

The non-solvated crystalline form "A" of 3-(-4-cynnamyl-1-piperazinyl)-iminomethylrifamycine SV finds application in the therapeutical practice. It represents a crystalline substance with absorption maximum of the infrared spectrum at 1644, 1585, 1340, 1350, 1295 and 1290-doublet, 1238, 1213, and triplet with low intesitivety at 726, 735 and 760 cm-1, as well as with characteristic diffraction maxima at 9,25 and 9,50 theta -most-intensive at 12,22 and doublet at 13,10 and 13,33 theta of the X-ray diffraction diagram. The obtaining of the non-solvated crystalline form "A" consists in the isolation of 3-(-4-cynnamyl-1-piperazinyl)-iminomethylrifamycine obtained in medium of indifferent organic solvent, preferably tetrahydrofuran or chloroform, and its dissolution in isopropanol or acetone or a mixture of both at a temperature from 30 DEG C. up to the ebullition temperature of the respective solvent. The substance possesses a high resoptionability, a high serum concentration, stability and chemical resistance.