We don't yet have an API to do this, however you can create the raw transaction using createrawtransaction, just sending zero units to the destination. Then add the OP_DROP and metadata manually into the appropriate output of that transaction, using which bitcoin transaction decoding/encoding library you have available for your development platform. You can see a specification of how the OP_DROP data should look at the bottom of this page:
http://www.multichain.com/developers/permissions-management/
And you can look at some permissions transactions created by MultiChain's grant and revoke commands to check that they match your understanding of how the OP_DROP metadata should be formatted.
