Split "shift-entered-notes" into seperate voices

I frequently use a double written note (f.e. a "c" followed by shift-"e") in trumpet parts. Normally the trumpet players have no problem reading their notes. But sometimes it is desireable to split such a part into two individual parts.

I know how to use voices. But if the rhytmic pattern is the same, is easier to enter a second voice with the "shift"note approach.

Is there a -easy- way to split such a part into two different parts?
Or am i missing the obvious solution?