Codeine pills.
A lot of them contain paracetamol but you can get rid of it with a simple cold water extraction.
Unless you're asking something else. Lean is just codeine and promethazine, everything else is just for flavor (don't think you could get powdered sprite anyway lol... Or maybe from one of those soda machines).
The entire point of lean is to sell extremely overpriced codeine to people who want to be hot shit. I'm not accusing you of anything but I don't see the point of "solid lean" except as a selling point.
If you want an equivalent experience just use codeine pills and if you want the added sedation take a benadryl.