There have been some (rare) claims that the Robocop movies carry an antidrug message to some extent, however that seems to be far from the actual truth. Even putting aside the fact that, after decades and countless interviews none of the filmmakers ever mentioned or hinted an antidrug messages, there is nothing in the movie that would support that claim.
The first two RoboCop movies are a hard R material, presenting a dark and dystopian world, filled with corruption, greed, murder, prostitution and - heavy drug use - it's a part of the crime scene and dark environment. In the first movie most of the characters use coke, and they use it heavily. From corporate guys like Bob Morton to gang/drug dealers such as Clarence's gang, coke is an ever present drug in the film. As a matter of fact, the movie's major shootout scene takes place in a coke factory.
The scene was never meant to be an antidrug imagery, and in fact was an homage to western movies, showing a "new sheriff cleaning up the town". There is a shot of Robocop stepping over and crushing the vials of cocaine, but the meaning of that image is that of a triumph of law and justice, justice trumping over crime
The drugs, or in the case of the first movie, cocaine, is ever present throughout the movie with the villainous characters sniffing coke of small vials throughout the film
In the second film, as in the first, drugs are omnipresent, although this time the main drug is a fictional designer drug called Nuke. It is puzzling that, simply because the movie centers around drug lords and heavy drug use and Robocop is fighting them, that there is a claim of some sort of antidrug message in the film, whichm, as far as drug use in the story, is no different that what cocaine was in the first. A shot of Robocop yet again crushing a drug is shown.
There is nothing that would indicate that drugs are bad in the movie other than Duffy and Angie's "hunger pains", and there are no consequences of drug use shown. Just the opposite, everyones actually shown as feeling really good and enjoying those, even the RoboCop II monster gets a high and all the hydraulics raise him by the end when he is enjoying the ecstasy and comfort of his drug.
RoboCop 3 is completely drug free
Perhaps what could give some the idea of the movies or at least one of the movie's being an antidrug message is the PSA from Peter Weller that he did in 1990 in conjunction with promoting the movie