Texas must reveal the source of the drugs it uses for executions.
Its Supreme Court doesn't believe doing so will harm the supplier and impede lethal injections.
Major pharmaceutical firms banned the sales of lethal injection drugs a few years ago.
Since then, Reuters reports most states have kept the suppliers of their drugs secret.
That has prompted lawsuits on behalf of death row inmates.
Lawyers have argued that prisoners could be subjected to unconstitutional suffering.
