Chemist’s brought in toothpaste urgently (7)
I believe the answer is:
pasteur
'chemist's' is the definition.
(Pasteur is an example)
'in toothpaste urgently' is the wordplay.
'in' indicates a hidden word.
'PASTEUR' is hidden in the letters of 'toothpaste urgently'.
'brought' acts as a link.
(Other definitions for pasteur that I've seen before include "He developed the partial sterilization of milk" , "Louis --, French chemist and microbiologist" , "French chemist and biologist (1822-1895)" , "He invented a method to stop milk causing disease" , "French scientist" .)