The invention provides a method of assembling a device and a kit suitable for administration to multiple patients comprising a multi-dose pharmaceutical composition of nasal analgesic in the form of a nasal spray. The present invention also provides a method for reducing the respiratory depressant effect associated with diamorphine administration, the method comprise a single dose pharmaceutical composition comprising lyophilized diamorphine and a diluent for reconstitution, wherein the dose of diamorphine is 0.1 mg/kg body weight.