what is the general chemical composition of the methadone drug?

is for a biology speech about drugs.... no, were not sick ppl addicted to drugs if thats what ur thinking(some ppl will tell me that ¬¬), the point of these thing is to know about them, how to prevent the use of it, and also know the effects of the human body and stuff like that..

well.. my group for the speech has to talk about methadone and i got the part of looking for the chemical composition... so some 1 help me =)

: http://alcoholdrugstreatment.info/what-is-the-general-chemical-composition-of-the-methadone-drug