Answer:
1) 0.391 mg 2) By resizing the semi-permeable membrane and reducing the saturated drug concentration from 100% to 60% (i.e. from to ).
Explanation:
1) The total amount of released drug at time 't' is:
Where:
H is the length of the device = 1 cm,
D is the diffusion coefficient of the drug
K is the partition coefficient = 10
is the saturated drug concentration in the polymer matrix
is the radius of the device = 250 μm
is the radius of the cylindrical space = 100 μm
t is the released time = 48*3600 s = 172800 s
Therefore:
2) For a membrane-controlled device, the released rate can be controlled (i.e. decrease or increase) by resizing the semi-permeable membrane. In addition, the saturated drug concentration should be reduced from 100% to 60% (i.e. from to )