A drug having a muscle relaxing effect can be prepared by binding negatively charged gold nanoparticles having a size of 1.4 nm fitted to synaptic clefts to choline through ionic bonds, thereby inducing gold-sulfur bonds in the Cys loop of an acetylcholine receptor in neuromuscular junction, and thus blocking the electric current induced in signal transduction from a nerve to a muscle, thereby blocking neuromuscular transmission chemically and physically. When the reverse is administered after surgery, the gold-sulfur bonds are broken due to the re-flow of the electric current, and thus the gold nanoparticles are again released and metabolized into neuromuscular junction. Further, such muscle relaxing effect can be applied as an anticonvulsant.
