Birthday invitations

My son is in preschool and his birthday is coming up, He wants to invite a few friends in his class to his party, I dont know the kids or the parents but Im ok with him inviting them, Should i send the invitations to school with him? I dont know any other time he would be able to invite tnem, but i also dont want him to makw any other kids who is not invited sad or jealous, or cause any distractions in his class..