A pharmaceutical company recently released a new drug capsule to the market, which is spherical in shape. An independent testing firm is requested by the Government to carry out several tests on this new drug. One of these tests is the estimation of the dissolution time. The following information is available to you: (1) The solubility of the drug in the solution is constant. (ii) The dissolved active ingredient of the drug has a constant diffusion coefficient (D) in the solution, and the diffusion flux equation is J = -D dC/dx (ii) The dissolved active ingredient is consumed in the gastric fluid, according to a first-order kinetics (moles consumed per unit volume of solution and per unit time). The rate constant for this consumption is k, and the chemical reaction rate per unit volume is R = kC. The fluid in the stomach can be assumed to be quite large relative to the size of the capsule. (iv) At quasi-steady state: Dd Pa()- kC = 0 With the boundary conditions r= R;C = Co and r> :C = 0, show that the solution for the concentration distribution is (use C = f(r) /r) Where kR2