<p>Antibiotic heparinates which have prolonged anticoagulant and antibacterial activity against gram-negative and antibiotic-resistant strains when applied topically are prped. by combining an aqs. soln. of sodium heparinate of pH 8.8.5 with an aqs. soln. of polymyxin, streptomycin, neomycin or kanamycin sulphate having a pH of 5-6 and separating and purifying the resulting difficulty soluble antibiotic heparinate with a mixture of 50 ml. of ethanol and 1250 ml. of acetone for each 250 - 300 ml. of aqs. medium.</p>
