A pump-type dispenser for dispensing predetermined doses of medicament in droplets or in spray form to the nasal area incorporates a rigid vial for medicament, an expandable pouch located within the rigid vial, a nasal screen, a one-way actuation mechanism, a one-way valve mechanism in the nozzle area and a spring element, both the valve mechanism and the spring element being formed as integral portions of the pump body. The one-way valve mechanism in the nozzle area ensures a one-way movement of medicament from the dispenser, thereby preserving substantially perfect sterility of the medicament in the dispenser, without requiring the use of preservatives. The one-way actuation mechanism enables the user to load and dispense a uniform quantity of medicament with a uniform actuation force and speed via a single continuous motion of the actuation mechanism. The rigid vial/expandable-pouch combination facilitates improved long term use, as well as uniformity of dosage independent of the pump orientation.