A sustained release formulation by using dimeticone as the dispersion medium, which includes active ingredient (e.g., drugs against parasites, insecticides, NSAIDs, antibiotics, sex hormone like agents or oily soluble vitamins) and dimeticone as the medium. Suitable stabilizer, antioxidant, local analgesics and material for sustained release may be added. The formulation is bio-compatible, stable and injectable.