The nonaqueous solvents presently in use as parenteral vehicles possess certain disadvantages or have limited application. The silicone fluids have certain physical, chemical, and biological properties which would appear to make them suitable for parenteral formulations. Accelerated thermal and light stability studies were carried out on a dimethyl silicone fluid of 20 centistokes viscosity and corn oil using menadione as the medicinal compound for study. Based on predictions from the accelerated thermal studies, it was found that the dimethyl silicone fluid was superior to corn oil. Corn oil was found to be superior to the dimethyl silicone in retarding photodegradation of menadione at room temperature. Since greater emphasis must be placed on the ability of the vehicle to retard thermal changes in a chemical compound, the experimental results indicate that the dimethyl silicone fluid of 20 centistokes viscosity is superior to corn oil as a vehicle for menadione.