Dr. Roger Guillemin, a recipient of the Nobel Prize in medicine, and Edmund G. Brown Jr., former governor of California, have been elected to the board of ICN Biomedicals, a subsidiary of Costa Mesa-based ICN Pharmaceuticals. ICN Biomedicals' board now totals six. Guillemin is a resident fellow and chairman of the Laboratories for Neurobiology at the Salk Institute in La Jolla and adjunct professor of medicine at the medical school of the University of California at San Diego. He was awarded the Nobel Prize in medicine in 1977. Brown was governor in 1975-83. He was California's secretary of state in 1971-75 and is now with the Los Angeles office of Reavis & McGrath, a New York-based law firm. ICN Biomedicals is a maker of research chemicals and instruments and is a major supplier of research products to the biotechnology industry.