an apparatus , located downstream of a packaging line for packaging of blister packs , works in conjunction with a carton ready - making line and comprises three devices positioned along a conveyor having an upper surface fitted with crosspieces to delimit seats designed to receive said blister packs . the first device transfers the blister packs from the packaging line to the seats , keeping the blister packs with the blisters turned upwards , while the second device , positioned downstream of a station , fills empty seats , where faulty blister packs where placed and from where the faulty blister packs where removed , with non - defective blister packs , the second device feeding itself with non - defective blister packs taken from the seats . the third device forms stacks of blister packs , folds an information leaflet , and inserts the stacks , together with the leaflet , into cartons coming from the carton ready making line .