To acquire and distribute free of charge for the benefit of citizens of the State upon request by physicians licensed in Illinois to practice medicine in all of its branches or by licensed hospitals in the State diphtheria antitoxin, typhoid vaccine, smallpox vaccine, poliomyelitis vaccine and other sera, vaccines, prophylactics, and drugs that are of recognized efficiency in the diagnosis, prevention, and treatment of diseases; also biological products, blood plasma, penicillin, sulfonamides, and other products and medicines that are of recognized therapeutic efficiency in the use of first aid treatment in case of accidental injury or in the prevention and treatment of diseases or conditions harmful to health; provided that those drugs shall be manufactured only during the period that they are not made readily available by private sources. These medications and biologics may be distributed through public and private agencies or individuals and firms designated by the Director as authorized agencies for this purpose.