Google Spreadsheets: Filter from an already "uniqued" values (or vice versa)

I would like to know if and how I can filter a list of values which was already created by the unique() function?

Example:

Suppose I have a column of values with duplications.

Abc 433Gal 653Dov 123Gal 653Dov 124

I operated Unique function on them to receive:

Abc 433Gal 653Dov 123Dov 124

and now I need to have all the values which does not contain Gal for example.So, my final column should be:

Abc 433Dov 123Dov 124

Until now I tried variations of the following:

=UNIQUE(FILTER(A1:A50), "<>Gal*"))

How can I achieve that?