Backup take too much time

Hello,

I have Oracle 12.2.0.1.0 on AIX.

I'm taking backup using below command

expdp User/Password@sid directory=BACKUP_DIR_BEFORE dumpfile=bkp_$now%u.DMP logfile=prod_bkp_$now.log METRICS=y EXCLUDE=statistics,TABLE:\"IN \(\'HAND\',\'HANDOFF_TMP\'\)\" direct=y filesize=50G cluster=n parallel=8

and for Environment reasons, I'm not able to use RMAN now.

The backup consume 10 Hours daily.

There is a specific table which take the 90% of the time.

this table size is 224 GB and have two columns of type xmltype and varchar

how can i make the backup faster, how can i check if there is a fragmentation in this table, and if exist, how to solve this.