The invention relates to improvements in drug delivery devices and particularly those for dispensing a metered dose of medicament. Apparatus (10, 110) is provided for dispensing medicament wherein at least a portion of one or more of the internal surfaces of components of the apparatus (10, 110) which come into contact with the medicament during storage or dispensing has a layer of one or more cold plasma preliminarised monomers bonded to at a least a portion thereof. <；IMAGE>； <；IMAGE>；
