Abstract:

In this paper, dynamic light scattering is employed to investigate the aggregation of heparin in aqueoussolution and to reveal the influence of ultrasonic treatment on the aggregation and stability of heparin. The resultsshow that heparin exists in aqueous solution in the form of aggregated species via multiple-molecule cross-linking,with the particle size of the aggregates increasing with the heparin concentration, that the aggregates cannot be com-pletely eliminated though the addition of sodium chloride leads to a reduction of aggregates diameter in a certain de-gree, and that ultrasonic treatment significantly restrains the heparin aggregation. When ultrasound with 30% ofpower percentage is applied for 3min, the aggregates with the diameter of 1001000 nm change into heparin mono-mers with the diameter of 110 nm, which means that ultrasonic treatment is effective in restraining the heparinaggregation. Moreover, disaggregated heparin powder with the diameter of 110nm can be obtained by the filtrationwith 100nm membrane and subsequent freeze drying. The disaggregated heparin remains stable after the storage formore than 64h at room temperatures.

Key words: heparin, ultrasound, aggregation, stability, dynamic light scattering