I have used daily pill containers and sent them for sleepovers with my kids. You can get small individual containers divided in three sections. I mark each section with the time meds are taken and put correct dose in each section. This way you will not send all his medication and only what is needed. It is a reliable method and helps whoever is giving the meds not to make a mistake. The containers are available at most drugstores and fairly inexpensive. It has worked well for us.