A slump in the share price of GlaxoSmithKline dragged the pharmaceuticals and biotechnology sector into the red on Wednesday as the drugmaker disappointed with a drop in quarterly sales and its full-year outlook.The company announced at midday that it has slashed its 2014 outlook as it reported a 4% fall in second-quarter revenue to £5.6bn.The drugmaker, which is in deep water over a bribery scandal in China, said operating profit declined 14% to £1.4bn as pharmaceutical and vaccine sales fell 4%, due to rising competition in the US respiratory market and the launch of a generic version of the company's heart pill Lovaza in April. GSK now expects to deliver 2014 full-year core earnings per share "broadly similar to last year", down from its previous estimate of 4-8% growth. The stock was down 6% at 1,461.99p by 14:27.Others in the sector such as AstraZeneca, Avacta, Vernalis, ReNeuron, Skyepharma, BTG and Hikma were all trading in the red this afternoon.Top performing sectors so far todayAutomobiles & Parts 8,290.78 +2.07%Electronic & Electrical Equipment 3,800.16 +1.81%Industrial Metals & Mining 1,230.21 +1.44%Mobile Telecommunications 4,482.12 +1.15%Technology Hardware & Equipment 1,073.47 +1.13%Bottom performing sectors so far todayPharmaceuticals & Biotechnology 13,049.29 -2.60%Electricity 9,699.99 -2.12%Forestry & Paper 11,137.58 -1.62%Chemicals 9,895.86 -0.69%Oil Equipment, Services & Distribution 24,058.82 -0.66%BC