You can try DIRECT=Y option with INDEX=N

If the TABLES are same in both PRDN and DEVL, do not drop the entire schema in DEVL DB. Just truncate all tables so that already allocated extents will be reused.

Increase the REDO LOG FILE SIZE to 100MB in DEVL, ensure checkpoint occurs after the redo fills in.
Or to minimize the redo log, before import alter all tables into NOLOGGING mode. This will definitely speed up your import process.