You cannot explicitly unbind a sharable inline default from a column. SAP ASE automatically unbinds or drops it from the column during drop table or alter table commands.
When you drop or alter a table, SAP ASE checks whether any inline defaults are shared with other columns. If they are, SAP ASE unbinds the columns from the inline default object without dropping the shared defaults.
If an inline default object is no longer used by any column, SAP ASE drops it.