Is there any way to run the definition of multiple stored procedure at a time?
Try right clicking on the database in Management Studio and selecting Tasks > Generate Scripts. The wizard that runs will let you create scripts for any objects in the database. In your case you'll want to select all "Stored Procedures".

In SQL Server 2008, you can click the "Advanced" button and change the value of the "Script DROP and CREATE" property to "Script DROP and CREATE" if you want to generate both scripts.

In SQL Server 2005, you may need to generate one set of DROP scripts and then another set of CREATE scripts (sorry I don't have an instance handy to test with).

See this link for more info:
http://blog.sqlauthority.com/2007/08/21/sql-server-2005-create-script-to-copy-database-schema-and-all-the-objects-stored-procedure-functions-triggers-tables-views-constraints-and-all-other-database-objects/