PT  - JOURNAL ARTICLE
AU  - Tyson Le
AU  - D. Ian Paterson
AU  - Neal M. Davies
AU  - John R. Mackey
TI  - Development and validation of a compact on-person storage device (SMHeartCard) for emergency access to acetylsalicylic acid and nitroglycerin
AID  - 10.9778/cmajo.20190147
DP  - 2020 Jan 01
TA  - CMAJ Open
PG  - E75--E82
VI  - 8
IP  - 1
4099  - http://www.cmajopen.ca/content/8/1/E75.short
4100  - http://www.cmajopen.ca/content/8/1/E75.full
SO  - CMAJ2020 Jan 01; 8
AB  - Background: Guidelines recommend that patients with coronary artery disease (CAD) carry and immediately use acetylsalicylic acid (ASA) and sublingually administered nitroglycerin at the onset of chest pain; however, compliance with these recommendations is poor. We designed and tested a compact on-person storage device for these medications.Methods: We designed an airtight, light-proof and chemically inert holder to carry four 81-mg ASA tablets and three 0.3-mg Nitrostat (nitroglycerin, Pfizer) tablets. After establishing the temperatures ranges in wallets and pockets, we tested nitroglycerin dissolution and release of the stored Nitrostat tablets across a range of relevant temperatures and a variety of tablet enclosure systems.Results: Microcalorimeter thermal conduction studies as well as dissolution and release testing showed that nitroglycerin tablets were stable at temperatures ranging from –20°C to 60°C for 1 week. In testing up to 24 weeks, 0.3-mg Nitrostat tablets enclosed completely in polytetrafluoroethylene (PTFE) performed similarly to those stored in the manufacturer’s borosilicate glass packaging across a wide range of temperatures relevant to on-person carriage. Real-world on-person testing for 24 weeks confirmed these results. Non-PTFE enclosures performed poorly.Interpretation: The PTFE enclosure with a PTFE-coated cap liner maintained long-term performance of 0.3-mg Nitrostat tablets under laboratory and real-world conditions. This storage device is now commercially available as the SMHeartCard to improve compliance and provide immediate access to emergency cardiac medications.