PURIFIED POLYOXYPROPYLENE/POLYOXYETHYLENE COPOLYMERS AND METHOD OF PREPARING THE SAME

摘要

The present invention comprises novel preparations of polyoxypropylene/polyoxyethylene octablock copolymers which retain the growth-promoting and immunity­enhancing activity of commercially-available preparations, but are free from the undesirable effects which are inherent in the prior art preparations. Because the polyoxypropylene/polyoxyethylene copolymers which comprise the present invention have a more homogenous population off molecules with fewer low molecular weight species than prior art preparations, the biological activity of the copolymer is better defined and more predictable. Moreover, the polyoxypropylene/polyoxyethylene copolymer of the present invention substantially reduces any risk to human health through the consumption of food animals since the copolymer hereof is not absorbed into the animal's edible tissue. Methods for preparation of the polyoxypropylene/polyoxyethylene copolymer of the present invention are also provided.