An inventive medical device includes an implantable device, such as an electrochemical sensor. The implantable device has an implantable portion configured for insertion into a patient, a contact portion configured for connection to another device, and an interconnecting portion connecting the implantable portion and the contact portion. A housing is provided that has a first part that is removably connectable with a second part to form a sterile packaging to seal the implantable portion against a surrounding environment. The first part comprises a first sealing surface and the second part comprises a second sealing surface and the first and second sealing surfaces interact to form a sealing area. The interconnecting portion of the implantable device extends through the sealing area. An inventive method of producing the medical device is also disclosed.