Hi, welcome on the Yuneec pilots forum.
There are many ready to use sistems for dropping, like this one:
Top Race Drone Clip Remote Control Object Launcher, Release and Drop Drone Delivery (180 Feet)
Amazon.com
The only limitation is the distance of the radio control, about 100~150 feet.
Here in Italy is available also this model :
Universale RC Drone Thrower Dispenser Telecomando Kit di Consegna Accessori per Sistema di Caduta d'Aria Sistema di Trasporto per la Consegna : Amazon.it: Giochi e giocattoli
www.amazon.it
that as a bigger range (500 mtrs).