Comparative Neutralization of Lung‐and Mucosal‐Derived Heparin by Protamine Sulfate Using In Vitro and In Vivo Methods

The objective of this investigation was to compare the number of heparin units neutralized by protamine sulfate as a function of heparin source, potency, and manufacturing process. Two experiments were conducted. In the first, results obtained by the in vivo response in rabbits were shown to agree with results obtained by the USP in vitro assay. The second compared the neutralization of several samples of sodium heparin by the USP in vitro procedure according to the parameters outlined. Results reported establish significant neutralization differences.