Table I shows the measured values of
endotoxin before and after a single passage through Sartobind Q15. By plotting the data in a diagram, it can be inferred that
a safe capacity of Sartobind Q15 membranes for
LPS can be set to 450–460 EU (see Figure 1). Within this range, the filtrate has concentrations < 0.5 EU/mL, which is considered
acceptable for injection into experimental animals. The process had no effect on the iodine and Gd concentration and a negligible
effect on pH.
Table II: Values of endotoxin, Ca2+ and Na+ before treatment with Sartobind 100. EU is European units.
The method was successfully applied to formulations containing Ca2+ and Na+ without affecting the ratio between them (see Tables II and III).
Table III: Values of endotoxin, Ca2+ and Na+ after treatment with Sartobind 100. EU is European units.
The method was ideal for preparing experimental formulations in exploratory phase where sterility of the starting materials
is not an absolute requirement. As such, the method gave us an opportunity to increase the throughput for screening of new
The authors would like to thank Dr. Ivar Martinsen, GE Healthcare, for the analysis of iodine and gadolinium of the samples
and Dr. Jann Vestby and Dr. Signe Marie Jensen for determination of endotoxin concentrations.
Gunnar Hagelin, D. Philos.*, is a senior research scientist and Lars Gøran Wistrand, PhD, is department manager, both in Analytical and Bioanalytical Chemistry, Research, Medical Diagnostics at GE Healthcare, Oslo,
Norway. *To whom correspondence should be addressed, email@example.com
Article submitted: Oct. 04, 2011. Article accepted: Jan. 31, 2012.
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