Drying kinetics of a multicomponent mixture of organic solvents

Drying kinetics of volatile organic solvents have been examined during the drying process of a pharmaceutical coating containing a multicomponent mixt ure of ethyl acetate, n-heptane, propanol-2, and toluene. A complete set of experiments was performed in two drying apparatuses, a laboratory air-drye r and an oven dryer, for a wide range of drying temperature, air velocity, initial coating thickness and drying time. An empirical kinetic model is us ed to predict the concentration of each organic solvent in the mixture duri ng the drying process. The results show that both drying conditions and sam ple characteristics affect significantly the drying rate of solvents.