Elixir Sulfanilamide was formulated with diethylene glycol as a solvent. Sulfanilamide (also spelled sulphanilamide) is a sulfonamide antibacterial drug. Sulfamethoxazole, a sulfanilamide, is a structural analog of "para"-aminobenzoic acid (PABA). In 1937, a drug known as "Elixir Sulfanilamide" was released without any clinical trials. The company tested the new product, Elixir Sulfanilamide, for viscosity, appearance and fragrance. In the 1930s, a new antibacterial drug called sulfanilamide was synthesized and was widely accepted. The sulfanilamide compound is more active in the protonated form. This was derived from the antibiotic sulfanilamide and became available in 1958. Sulfanilamide drugs are not like the antibiotics used to treat infections. Sulfapyridine (INN; also known as sulphapyridine) is a sulfanilamide antibacterial medication. In the laboratory, it can be prepared by halogenation of sulfanilamide followed by desulfonation. Then an excess but fixed volume of sulfanilamide and "N"-(1-naphthyl)ethylenediamine dihydrochloride solution is added.