US Patent 11744775 Pressure-regulating vial access devices and methods

In certain embodiments, a vial access device for removing liquid contents from a vial includes a piercing member extending from a base of an insertion member and a reservoir. The reservoir can be contained within the piercing member and the insertion member, such that the reservoir is introduced to the vial when piercing member is inserted into the vial. The piercing member is adapted to be opened inside the vial to expose the reservoir to the contents inside the vial. A locking mechanism can prevent the piercing member from being inserted into the vial unless the vial access device is fully coupled to the vial and/or prevent the piercing member from being withdrawn from the vial without uncoupling the vial access device from the vial.