I know this is an old thread, but this worked for me (for VB.Net). Hopefully it can help someone down the road:

​Add a reference to "Microsoft Office 12.0 Access database engine Object Library"

Dim dbe As New Microsoft.Office.Interop.Access.Dao.DBEngine

dbe.CompactDatabase("C:\folder\database.accdb",  "C:\folder\database_New.accdb", , , ";pwd=<database password>")