Process for preparing crude heparin

Claim 1

IN A PROCESS FOR THE PREPARATION OF HEPARIN WHICH INCLUDES AUTOLYSIS OF ANIMAL TISSUE, ALKALINE EXTRACTION OF THE AUTOLYSATE TO FORM AN AQUEOUS, HEPARIN-CONTAINING EXTRACT, AND DIGESTION OF SAID EXTRACT WITH ADDED ENZYMES, THE STEPS COMPRISING ADDING TO THE DIGESTED EXTRACT A FLOTATION AGENT COMPRISING A BASIC ORGANIC SUBSTANCE CAPABLE OF FORMING WITH THE HEPARIN IN SAID EXTRACT A HYDROPHOBIC HEPARIN COMPLEX,ADDING TO THE COMPLEX THUS FORMED A WATER-IMMISCIBLE ORGANIC LIQUID IN WHICH THE HEPARIN COMPLEX IS INSOLUBLE, AGITATING THE MIXTURE AND ALLOWING IT TO STAND FOR A SUFFICIENT LENGTH OF TIME TO PERMIT THE FORMATION OF THREE LAYERS COMPRISING AN AQUEOUS PHASE, AN ORGANIC LIQUID PHASE AND AN INTERPHASE OF SAID HEPARIN COMPLEX, MECHANICALLY SEPARATING SAID INTERPHASE FROM THE OTHER PHASES, AND SEPARATING THE HEPARIN FROM SAID INTERPHASE.