Crosslinked hemoglobin of extended shelf life and high oxygen transport capacity and process of preparing same

Claim 1

In the preparation of a crosslinked hemoglobin of extended shelf life and high oxygen transport capacity wherein a stroma-free hemoglobin solution is treated with an effector and crosslinked with a dialdehyde having carbon chains of 3 to 8 carbon atoms, the improvement which comprises contacting a stroma-free, concentrated hemoglobin solution with so much of an ox/gen-consuming reducing agent that the O 2 partial pressure diminishes to substantiall 0 mbar, contacting the deoxygenated product thus obtained with a physiologically tolerable effector and then, at a pH between about 6 and 8, with the dialdehyde, reducing the crosslinked product so obtained with about 5 to 20 times the molar amount of a carbonyl-group-specific reducing agent, diluting the solution with water, ultrafiltering and recirculating the solution until the content of un-crosslinked hemoglobin amounts to no more than about 15%, the crosslinking being effected before or during the ultra-filtration, and adding a reducing agent thereby to stabilize the solution.