There are many examples of it in the code datastore queries.
Here is one from the action module:
$_sp = array(
'search' => array(
"_profile_id = {$params['profile_id']}"
),
'skip_triggers' => true,
'limit' => 1000000
);
$_rt = jrCore_db_search_items('jrAction', $_sp);
If you could say what your trying to retrieve that would help answering the question.
From you query it looks like your trying to get a specific set of profile names.
$_sp = array(
'search' => array(
"profile_name = 'something'"
),
'limit' => 500
);
$_rt = jrCore_db_search_items('jrProfile', $_sp);
If you need multiple search strings then add to the array
$_sp = array(
'search' => array(
"profile_name = 'something'",
"profile_xxxx = 'xxxxxxxxx'"
),
'limit' => 500
);
$_rt = jrCore_db_search_items('jrProfile', $_sp);