The most common and most likely answer to this crossword clue is the 8 letter word CALAMINE
I've seen this crossword clue in Financial Times
C
A
L
A
M
I
N
E
Buddy explains!
The straight part
We know that "Lotion powder" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case lotion powder = calamine.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 CALAMINE mean?
CALAMINE noun- A pale pink powdered form of zinc oxide used in skin lotions.
- The zinc silicate mineral hemimorphite.
- To coat or treat with calamine.