General:
* Over-packed: Containing more than can be comfortably held.
* Under-packed: Containing less than is needed or expected.
* Tightly-packed: Packed very closely together.
* Loosely-packed: Packed with space between items.
Specific:
* Pre-packed: Packed in advance, often for sale.
* Vacuum-packed: Packed in a sealed container with air removed.
* Individually-packed: Each item is packed separately.
* Air-packed: Packed with air cushions for protection during shipping.
Figurative:
* Emotionally-packed: Full of strong emotions.
* Information-packed: Containing a lot of information.
* Action-packed: Full of exciting events.
These are just a few examples. The best prefix to use will depend on the specific context and the meaning you want to convey.