A sealed pharmaceutical container comprises a flange comprising an underside surface, an outer surface extending from the underside surface, the outer surface defining an outer radius ro of the flange; and an upper surface extending between the outer surface and an inner surface defining an opening in the sealed pharmaceutical container. The upper surface comprises a sealing region extending between the opening and the outer surface and comprising a radius rsr that is less than ro. The sealed pharmaceutical container also comprises a sealing assembly comprising sealing portion in contact with the upper surface at a lower surface of the sealing portion and a cap compressing the stopper against the upper surface. After compression, the sealing portion of the stopper comprises a compressed radius rsc that is less than rsr adjacent the upper surface.