The bottom line is... I work at a major drug chain as a store manager and personally do the process. We do not ever throw ANY drug in the dumpster (except for maybe a swallow of cough medicine). All drugs are sent back to the distribution center, then either incinerated, or forwarded to the wholesaler for store credit, which I am pretty sure they dispose of them the same way. It is very strict, even all RX trash bags have to be saved and returned to the DC for "proper disposal" if were ever caught throwing RX trash out in the dumpster, we would be fired, and possibly fined if any patients info was ever found.
Hope that answers all. We are very strict on this because of all the "Dumpster Divers" we get...