Abstract
By means of a two-step chromatographic technique propionyl erythromycin. and erythromycin can be separated from the normal blood components and then from each other. The relative amounts of each form of the antibiotic can be determined on bioautograph plates by comparison of the zone sizes with those of a set of reference standards. Using this method, we have found that when propionyl erythromycin is added to blood there is an initial rapid hydrolysis to erythromycin. The hydrolytic rate decreases markedly with time, however, and overall is much slower than in buffer solution at the same pH. The rate of hydrolysis in blood differs with different animal species.
