Abstract: The disclosure provides a method of producing a platinum colloid comprising reducing platinum ions by the use of a platinum ion solution, water, a nonionic surfactant, a pH adjusting agent, and a reducing agent, wherein the platinum ion solution contains platinum at a concentration of 20 w/v %, the nonionic surfactant is polysorbate 80, the pH adjusting agent is an alkaline metal salt, the reducing agent is a lower alcohol, the volume of the water is from 600 to 660 times that of the platinum ion solution, the volume of the nonionic surfactant is from 0.20 to 0.30 times that of the platinum ion solution, the volume of the pH adjusting agent as a 5 w/v % aqueous solution is from 10 to 30 times that of the platinum ion solution, and the volume of the reducing agent is from 27 to 37 times that of the platinum ion solution, as well as the platinum colloid produced by the method.

Abstract: The disclosure provides a method of producing a platinum colloid comprising reducing platinum ions by the use of a platinum ion solution, water, a nonionic surfactant, a pH adjusting agent, and a reducing agent, wherein the platinum ion solution contains platinum at a concentration of 20 w/v %, the nonionic surfactant is polysorbate 80, the pH adjusting agent is an alkaline metal salt, the reducing agent is a lower alcohol, the volume of the water is from 600 to 660 times that of the platinum ion solution, the volume of the nonionic surfactant is from 0.20 to 0.30 times that of the platinum ion solution, the volume of the pH adjusting agent as a 5 w/v % aqueous solution is from 10 to 30 times that of the platinum ion solution, and the volume of the reducing agent is from 27 to 37 times that of the platinum ion solution, as well as the platinum colloid produced by the method.

Abstract: The present invention provides a composition comprising precious metal particles for treating or preventing a psychiatric symptom. The composition of the invention is able to improve various psychiatric symptoms and useful for treating or preventing psychiatric disorders.

Abstract: The present invention provides a composition comprising precious metal particles for treating or preventing a psychiatric symptom. The composition of the invention is able to improve various psychiatric symptoms and useful for treating or preventing psychiatric disorders.