Shares in Swiss drugs industry supplier Lonza fell over 4% on Monday after Deutsche Bank analysts downgraded the stock as they expect the strong Swiss franc and a tougher environment to weigh.

"We appreciate Lonza's strategy and underlying progress, but external headwinds are just too massive to be offset," analysts at Deutsche Bank said in a note. Deutsch Bank cut its rating to "sell" from "hold" and slashed its price target to 61 francs from 78 francs.

Fewer incremental cost savings in 2011 and a tougher environment as a result of rising raw material prices and very low approval activity from the Food and Drug Administration in the United States were also likely to hit Lonza, the analysts said.

Lonza Chief Executive Stefan Borgas warned last week the strong Swiss franc would be a major challenge for the Swiss economy in the next five years. The franc rose about 16% versus the euro last year.

"Upside risk might emerge from a weaker franc, new contract wins, accretive M&A, a higher FDA approval rate, an improved macro outlook, and less aggressive competition," the Deutsche Bank analysts said.