Question

Which theory takes into account that a thin film is created by the solution of the solid at the solid-liquid interface?

(a) Interfacial barrier model

(b) Diffusion layer model

(c) Penetration or surface renewal theory

(d) Danckwert’s model

I had been asked this question in an interview for internship.

The above asked question is from Physicochemical Factors Affecting Drug Absorption topic in division Absorption of Drugs of Drug Biotechnology

Answer 1

Right choice is (b) Diffusion layer model

The explanation is: Diffusion layer model states that solution of a solid form a thin film or layer at the solid-liquid interface which is called as the stagnant film or diffusion layer which gets saturated with the drug. This step is rapid.