Biomedical Engineering Reference
In-Depth Information
CP (and hence the capacity) dependence on the amount of dimethyl ether
present. Also, as depicted in Figure 13.13, the size of the micellar region scales
nicely with solvent composition.
These results serve to show that using mixed solvents allows not only
reduction of the operating pressure, but also gives better control over the
solvent selectivity and capacity. While these results illustrate an improved
NCM control, the next development hurdle was to demonstrate that NCM can
be used to make drug-loaded micelles. If so, can NCM allow for improved
drug loading?
d
n
4
y
3
n
g
|
1
13.5 Loading PEG-b-PCL with a Cancer Drug
Towards this end, Tyrrell et al.
20
investigated PEG-b-PCL (5k-b-5k) with
tamoxifen in trifluoromethane. An example of their results is shown in
Figure 13.14. The CP of the drug is lower than that of the copolymer, which
Figure 13.15
Drug loading content of tamoxifen and paclitaxel in PEG-b-PCL (5k-
b-5k). Error bars represent the standard deviation of n 5 3 for
tamoxifen and n 5 5 for paclitaxel. Literature values for paclitaxel
22
were obtained by a solvent evaporation method using THF. A
literature reference was unavailable for tamoxifen in PEG-b-PCL.
(Reproduced from Tyrrell et al.
20
with permission from the American
Chemical Society.)
