Methods of making components for a medicinal delivery device are described, in which a primer composition comprising a silane having two or more reactive silane groups separated by an organic linker group is applied to a surface of a component, then a coating composition comprising an at least partially fluorinated compound is applied to the primed surface. The surface may be a polymer surface. Corresponding coated components and a medicinal delivery device are disclosed. Methods of making metal components are described in which a coating composition comprising an at least partially fluorinated compound is applied to a surface cleaned with a solvent.