### Clue: Directed towards back street to get unusual kind of medicine (7)
### Answer: NOSTRUM 
 ### Explanation: Definition: kind of medicine
 **Reversal of**(… back) ON(directed towards/aimed at …, as in "attacks on his integrity") + ST(abbrev. for "street") **plus**(to get) RUM(unusual/odd).
Defn: … prepared by an unqualified person.