A U.S. pharmaceutical executive is defending his price boost of a key antibiotic by 400 percent to almost $2,400 a bottle as a "moral requirement," a claim that drew an immediate rebuke from the country's drug regulatory chief.Nostrum Pharmaceuticals president Nirmal Mulye told The Financial Times he had a "moral requirement to sell the product at the highest price," pushing the price of the antibiotic mixture called nitrofurantoin from $474.75 to $2,392 a bottle. The World Health Organization calls the drug an "essential" medicine for lower urinary tract infections.Mulye told the newspaper, "I think it is a moral requirement to make money when you can. This is a capitalist economy and if you can't make money you can't stay in business." He compared his decision to increase the price to that of an art dealer selling "a painting for half a billion dollars" and said he was in "this business to make money."The Food and Drug Administration commissioner, Dr. Scott Gottlieb, rejected Mulye's justification for the price hike, saying, "There's no moral imperative to price gouge and take advantage of patients."He said the FDA "will continue to promote competition so speculators and those with no regard to public health consequences can't take advantage of patients who need medicine."The dispute over the antibiotic's price comes in the midst of periodic complaints by President Donald Trump that drug costs are too high in the United States.In May, Trump unveiled a plan to try to increase competition among drug makers in an effort to lower drug prices."The drug lobby is making an absolute fortune at the expense of American patients," Trump said.