This review aimed to map the existing patents of double-chamber syringes that can be used for intravenous drug administration and catheter flush. A search was conducted in the Google patents database for records published prior to 28 October 2020, using several search terms related to double-chamber syringes (DCS). Study eligibility and data extraction were performed by two independent reviewers. Of the initial 26,110 patents found, 24 were included in this review. The 24 DCS that were found display two or more independent chambers that allow for the administration of multiple solutions. While some of the DCS have designated one of the chambers as the flushing chamber, most patents only allow for the sequential use of the flushing chamber after intravenous drug administration. Most DCS were developed for drug reconstitution, usually with a freeze-dried drug in one chamber. Some patents were designed for safety purposes, with a parallel post-injection safety sheath chamber for enclosing a sharpened needle tip. None of the DCS found allow for a pre- and post-intravenous drug administration flush. Given the current standards of care in infusion therapy, future devices must allow for the sequential use of the flushing chamber to promote a pre-administration patency assessment and a post-administration device flush.
Keywords: double-chamber syringes; flushing; patent review; vascular access devices.