The Costa Mesa developer of a drug for treatment of early stage AIDS plans to file a third request with the Food and Drug Administration for permission to expand testing, according to the firm. ICN Pharmaceuticals Inc. said its Viratek subsidiary has submitted additional information to the FDA "over the past 30 days" and is "in the process of reapplying . . . as soon as additional data is available." ICN acknowledged that for the second time in five months the FDA had refused to authorize additional testing of the drug ribavirin. FDA officials said ICN had still not demonstrated that the drug "meets the agency's safety and efficacy standards." The FDA action leaves ribavirin on "clinical hold," a regulatory limbo that permits no additional clinical experimentation with the drug.