Experimental design and optimization of the hydrogenation process of soybean oil

The hydrogenated soybean oil was prepared by catalytic hydrogenation process in order to be used as a pharmaceutical excipient for hot melt applications. To optimize the hydrogenation process and produce a product whose quality conforms to the hydrogenated vegetable oil type I in the US Pharmacopoeia (USP 24), a central composite design was applied. The influence of three main process parameters, i.e. amount of catalyst, hydrogen pressure and temperature on the hydrogen consumption, the time required for the completion of the reaction and the reaction rate as well as the quality of final products was studied. The increase in the amount of catalyst and temperature significantly enhanced the reaction rate. However, at higher temperature, the acid values of the final products also increased. The thermal behavior of the product showed tolerance to high temperature exposure, i.e. 80-120°C, where unchanged exothermic peaks were determined in the thermograms before and after exposure. This novel excipient is applied in a next step in the hot melt coating application for the preparation of modified release formulations.