Hand operated devices for administration of a medicament

A handheld assembly for dispensing a medicament to a subject, the assembly comprising:

• a unit dose form containing the medicament;
• a shell configured for housing components of the handheld assembly;
• a plunger at least partially enclosed within the shell and extending from the shell and configured to express the unit dose form;
• a dispense button at least partially enclosed within the shell and extending from the shell and in slidable communication with the shell;
• a drive member located within the shell and in communication with the dispense button;
• a plunger escapement member rotatable about an axis within the shell and having more than one ramp wherein each ramp has a predetermined profile;
• wherein a first motion of the dispense button causes the drive member to translate along a first ramp of the plunger escapement member readying the assembly for dispense, and wherein a second motion of the dispense button causes the drive member to translate along a second ramp of the plunger escapement member extending the plunger to express the unit dose form, and wherein the unit dose form further comprises an internal piercing member located inside the unit dose form and configured to puncture a lidding material of the unit dose form from the inside upon the second motion of the dispense button.