Patent ID: 8573403

Claim:
A blister sheet having a planar back and provided with a blister having first and second pairs of side walls and a front face held spaced from the plane of the back of the sheet by the side walls, the blister being of elongated shape and the first pair of side walls being longer than the second pair of side walls, the first pair of side walls being so formed that they yield under finger pressure applied to the front face of the blister while progressively collapsing from the front face in response to increasing finger pressure being applied to the front face, and the second pair of side walls responding to the finger pressure by tilting towards one another so that any medication dose which may be located against a tilting side wall is displaced towards a position lying beneath the front face and from which it can be ejected by increasing finger pressure, and wherein the first pair of side walls are formed with parallel steps, and the second pair of side walls have their central regions devoid of steps or corrugations and of planar trapezoidal shape so that they can tilt towards one another about their edges where they join the portions of the blister sheet from which the associated blister protrudes.