Valeant Pharmaceuticals International Inc. shares dropped 5.4% in premarket trade on Monday on news that the Food and Drug Administration failed to approve the company's lotion intended to treat plaque psoriasis. In a "complete response letter" notifying the company of the decision, the regulator noted questions about pharmacokinetic data, but did not specify problems with how well the product, Duobrii, works, nor with chemistry, manufacturing and controls processes, the company said. Valeant says it plans to work with the FDA to resolve the matter. Valeant shares have surged 60.6% over the last three months, compared with a 1% rise in the S&P 500 and a 0.6% rise in the Dow Jones Industrial Average