A metered dose inhaler canister combination comprises a canister 102 configured for containing a pharmaceutical composition, the canister 102 having a canister base 106, a side wall 108 extending from the canister base 106, an open end 110 distal from the base 106 and a first cooperating formation 112 arranged at said open end 110 and extending generally distally from said canister base 106； a shroud 104 having a shroud base 116 and a side wall 118 extending from the shroud base 116 to a waist 124, the base 116 and side wall 118 defining a vessel configured to receive the canister 102 therein, the waist 124 defining an aperture of constricted width configured to receive the canister 102 therethrough, and a second cooperating formation 114 extending generally distally from said waist 124, wherein the respective first and second cooperating formations 112,114 adopt an engaged condition in which the canister 102 is retained within the shroud 104.
