Pharmacosmos DEAE-Dextran
DEAE-Dextran (diethylaminoethyl dextran) is a polycationic derivative of dextran and can be used as a component/adjuvant in vaccines, for transfection and gene therapy, as a stabiliser of proteins and in drug delivery.
Pharmacosmos DEAE-Dextran is based on our world-leading dextran products and produced at our state-of-the-art, GMP-approved facility in Denmark.
As part of Pharmacosmos’ commitment to quality, our DEAE-Dextran is developed and manufactured at the highest quality and according to the same advanced standards and requirements as applied in the development and manufacturing of our world-leading dextran products.
DEAE-Dextran
DEAE-Dextran is synthesised by the reaction of dextran with (2-chloroethyl) diethylammonium chloride in an alkaline solution.
DEAE-Dextran is a polycation containing three basic groups with different pKa values. There are two tertiary groups: one in the single substituted glucose unit that has a pKa value of approximately 9.2 and the tertiary group in the tandem substitution that has a pKa value of approximately 5.5.
The quaternary nitrogen cannot be protonated and cannot have a true pKa.
Titration of DEAE-Dextran
This figure shows the titration curve from the titration of DEAE-Dextran after alkylation.
The grey vertical bar shows the point at which the excess sodium hydroxide is titrated. The light blue vertical bar shows when the tertiary group with pKa of approximately 9.2 is titrated, and finally the dark blue vertical bar shows when the tertiary group with pKa near 5.5 is titrated.
The total amount of nitrogen can be calculated from the titration curve or by Kjeldahl-analysis. The nitrogen content of approximately 3.2% is equivalent to one charged group per three glucose units.
As seen in the above figure, DEAE-Dextran contains more tertiary groups than quaternary amino groups. Calculated on the amount of nitrogen in the DEAE-Dextran, approximately 2/3 of the nitrogen content belongs to the tandem substitution.
DEAE-Dextran is stable in solution at ambient temperatures and at pH values ranging from pH 4-14. The dry powder has good stability.
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