SQL & PL/SQL

My oracle version is :-

Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production

PL/SQL Release 11.2.0.3.0 - Production

"CORE 11.2.0.3.0 Production"

TNS for Linux: Version 11.2.0.3.0 - Production

NLSRTL Version 11.2.0.3.0 - Production

Table is truncated using below code :-

'TRUNCATE TABLE '||p_table_name||' DROP STORAGE';

For one of the table( Partition) having 40 M records , the truncate run for 1 hours and 30 mins and rest small table tables few seconds.

How can we speed up the truncate statement or any other approach.

Thanks in advance.