PROCESS FOR PREPARING OF STABLE TETRACYCLINE ANTIBIOTIC COMPOSITION

A method for preparing a stable antibiotic composition containing a high concentration of the antibiotic in solution; characterized by reacting a tetracycline antibiotic with a slurry consisting of a pharmaceutically acceptable alkaline earth compound and, if desired, polyvinyl pyrrolidone, in caprolactam or aqueous 2-piperidone to form an alkaline earth metal chelate/tetracycline and adjusting the value of ph, if necessary to achieve a solution, the antibiotic is selected from oxytetracycline, oxycycline, chlortetracycline and the pharmaceutically acceptable acid addition salts thereof, with the proviso that when the antibiotic is chlortetracycline, the alkaline earth compound is a compound of soluble calcium in the solution and when the antibiotic is oxytetracycline or doxycycline, the alkaline earth compound is a magnesium compound, soluble in that solution. (Machine-translation by Google Translate, not legally binding)