The S&P 500 was off 0.35% to 1,688.18 in afternoon trading Wednesday.
The Dow Jones industrial average fell 0.60% to 15,358.37, while the Nasdaq slipped 0.21% to 3,676.60.
The yield on a 10-year Treasury bond was down 0.18% to 2.71%.
The price of gold rose 0.98% to $1,333.40 per ounce.
Shares of Aliso Viejo drug maker Avanir Pharmaceuticals Inc. rose about 11% to $5.09 after the company announced a settlement agreement with New Jersey drug maker Sandoz Inc. The agreement allows Sandoz to sell a generic version of Avanir's Nuedexta called Anda. Nuedexta is used for the treatment of pseudobulbar affect, a disorder that causes sudden involuntary outbursts of crying or laughing. Avanir had a recent market value of $739.29 million.
Irvine-based healthcare software maker Quality Systems Inc. shares were off about 4% to $21.45 for a market value of $1.28 billion. KeyBanc started coverage of the company with an "underweight" rating.
Shares of Irvine-based medical device maker Biolase Inc. plunged about 32% to $1.23 for a market value of $38.94 million. The company said Tuesday that Comerica Bank waived the company's non-compliance on a loan agreement condition until Sept. 13.