A dispensing apparatus for dispensing a unit dose of a pharmaceutical substance, in particular for intranasal administration, is described. The apparatus includes a nozzle unit having a safety cap thereon and an actuating device. The safety cap has legs, which can locate within the actuating device. Upon mounting the nozzle unit on the actuating device, the legs on the safety cap push down a ram in the device against the action of a spring, until the head of the ram engages over a shoulder. The ram is released by depression of a button on the device and by relative movement of two parts of the device.