Medical Mailing Lists For Marketing

Where is the best place to get marketing mailing lists for the UK?
I’m in marketing, but am struggling with this issue. The key people we are trying to target are in the medical and pharaceutical industries. Any ideas?
1)The Pharmaceutical Marketing Society, UK
2)Cegedim ltd. UK, Nicholas centre,Maidenhead, Berkshire, UK
Both will be in position to give data on pharma and medical industry
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