This chapter begins with a discussion on the separation of variables in 2-D cylindrical coordinates. The method of multiplicative separation of variables was applied to solve Laplace's equation in cylindrical coordinates. A profile for the concentration inside the walls of a hollow cylinder was developed in terms of Bessel functions. The method exhibited superior convergence properties. The chapter explains a model for drug release from a hollow cylinder. In a recent study, several dialysis equilibrium techniques were evaluated for the study of topical liposomal gel formulations to deliver hydrophobic drugs. It was stated that the kinetics of drug release was essential to a rational design of delivery systems. Therefore, it is important to study how drug molecules diffuse through the walls of these semipermeable membranes. The chapter concludes with a discussion on the analytical solution of the transport model in 2-D cylindrical coordinates.