Removing duplicates from a column with text strings

Hi, I have a column of text from which I have removed duplicates using the usual method. Now the resulting column that I am left with can also have duplicate values as the data is not clean. Some of the inconsistency in the data is as follows:

1) 'ABC (P2400)' in one row and 'ABC (2400)' in another row, which are essentially the same.
2) 'ABC' in one row and 'Case ABC' in another row, which are same too.
3) Inconsistency due to no. of spaces can also be there.

The text in the cells is mostly a multi-word description of the product type.

How do I obtain unique values from the column?