The most common and most likely answer to this crossword clue is the 8 letter word UNOPENED
I've seen this crossword clue in Financial Times
U
N
O
P
E
N
E
D
More clues leading to the result UNOPENED
- End up with one novel still in its wrapping
- Like problematic jar of marmalade? End up with one chucked!
- University man receiving old writing implement still in wrapping
- Cavorting nude outside, Frank gets barred
- Closed up one end unwisely
- Upper class newspaper boss maintains no writer is barred
- A French-English dictionary includes “enclose” for “shut”
- With cap still on, screwing one end up?
- Closed wild nude gathering? Nothing doing!
- Such a gift is still wrapped up
Buddy explains!

The straight part
We know that "still in its packaging" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case still in its packaging = unopened.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does UNOPENED mean?
UNOPENED adjective- Not yet opened; still closed