I think you have forgotten about drunken escapades of dutta earlier or maybe you think alcohol is a sacred "charna amrit" and drug is a vice. Alcohol and drugs are the same having different degree of power to give intoxication. NS has been giving these injections and any human body will get affected by this. This is a physical aspect. Nothing to do with character. He is not doing drug business.
Anyway I don't think dutta has become a drug addict as he said "these ppl think i'm addicted to injections". After he escapes from this place, injection saga will be forgotten as we all know how logical these CVs are. Dutta who was shown drunk so many times, never had any withdrawal symptoms, when he was in normal or happy mood.
Even if he has become a drug addict, it is only a physical aspect. How is it character assasination? He has always been a emotionally vulnerable person. He has been separated from nakku and his family after a short period of reunion, that itself came after long separation. His determination and strength comes only from nakku and his family's support. Once he escapes, gets them both, he will be normal. Drug addiction is a physical problem not a sign of character degradation.
Please don't jump to conclusions and also i request ppl make their own opinion after watching the episode. Many members in the forum say they are not watching LTL, still they are quick to comment on anything negative without even bothering to watch.
Thanks for the update.