Calculate the first order absorption rate constant Kabs, for transport of a lipophilic drug across the nasal mucosa if: the surface area of absorption = 110 cm? volume = 0.1 ml apparent permeability = 1.1 X 104 cm/sec The mucous layer poses a significant barrier to the lipophilic drug and the permeability coefficient across the mucous layer is 1.5 X 104 cm/sec. Determine the new first order rate constant of absorption. A weakly acidic drug (1 mg) having Ka (ionization constant) value of 1.48 X 10-5 is instilled in the nasal cavity (pH ~5). Assuming that the ionized species of the drug do not have appreciable absorption, determine the flux of weakly acidic drug across the nasal mucosa