A transdermal patch is designed to deliver Methadone. Before the drug is delivered across the skin, it diffuses through a rate$-$controlling membrane between the drug reservoir and skin. The surface area, thickness, diffusion coefficient, and partition coefficient K $($Oil$/$Water$)$ of the membrane is $10$ cm$2,100\backslash$mu m$,10-8$ cm$2$ sec$-1$ and $10,$ respectively. Calculate the permeability coefficient of this drug through this membrane.