Transdermal microneedle drug delivery device and method

A transdermal drug delivery device comprising:

• a reservoir for holding a drug;
• at least one microneedle in fluid communication with the reservoir through which the drug can be delivered transdermally;
• a housing surrounding the reservoir;
• a fastening element configured to conceal the housing from view during operation thereof;
• an injection unit housed within the housing, wherein the injection unit comprises a bottom cap;
• and
• an actuator for deploying the at least one microneedle, wherein the bottom cap comprises a first indentation or void with a first positon and a second indentation or void with a second position relative to the first position and wherein the first indentation or void lockingly engages one of a pair of protuberances on the actuator before actuation of the at least one microneedle and the second indentation or void locking engages with one of the pair of protuberances on the actuator after actuation of the at least one microneedle.