You are tasked with delivering $300mg$ of doxorubicin over $10$ days using a polyurethane membrane$-$based drug delivery device. You can assume steady$-$state diffusion through the membrane and that the drug concentration within your high$-$concentration donor reservoir remains constant along with perfect sink conditions in the surrounding tissue. The diffusion coefficient for this material drug combination is $D={10}^{-9}\frac{m^2}{s}.$ The thickness of the membrane should be $0\mathrm{.}5mm,$ and the maximum surface area should be $0\mathrm{.}05m^2.$ Calculate the drug concentration you should use in your device to release this quantity of drug over $10$ days.

$(5)$

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