The invention is provides a composition for sustained delivery of a biologically active agent comprising a biologically active mixture and a controlled release formulation. The composition protects the biologically active agent from being destroyed by the controlled release composition. The biologically active mixture includes the biologically active agent and a pharmaceutically acceptable protective carrier. The controlled release formulation includes a pharmaceutically acceptable, biodegradable, matrix forming material that is substantially insoluble in aqueous or body fluids and a pharmaceutically acceptable organic solvent. The biologically active mixture is combined with the controlled release formulation to form an emulsion, the delivery composition, which is then administered to a patient. The protective carrier can be an aqueous substance, a non-aqueous substance or a combination of both. The matrix forming material can be a polymeric material, a non-polymeric material or a combination of both. The organic solvent can have a solubility ranging from a high water solubility to a low water solubility.