Chemistry Reference
In-Depth Information
Toxic range
erapeutic range
Ine
ective range
Time
Figure 10.2:
Drug concentrations in the body as a function of time. The dashed line shows the un-
controlled dissolution of a pill, with two regions so low that the concentration would be
ineffective and another region high enough to be toxic. The solid line shows the goal of
controlled delivery, specifically a relatively constant delivery rate in the therapeutic range
for an extended period of time.
Figure 10.3:
A controlled release drug-delivery system that utilizes both siloxane elastomers and
fluids. The photograph was provided by the Dow Corning Corporation of Midland, MI.
mold-release agents, adhesives, protective coatings,
14
release control agents
for agricultural chemicals, encapsulation media, mold-making materials,
coatings, layers in high-tech laminates, and hydraulic, heat-transfer, and
dielectric fluids.1,
1,
3,
15-16
These applications are based on the same properties
of polysiloxanes just mentioned and also their ability to modify surfaces
