Naloxone is the drug used to block the effects of opioids. LE carry them, but at the cost of $4500 for two injectors. The Narcan spray is slightly lest costly iirc. I'm a uni student working on designing an auto-injector that could be used instead (the medicine itself is very cheap) and potentially to administer epinepherine too (also a case of cheap medicine - expensive administration device).
I've made some progress but have no mechanical design experience. I'm not optimistic about the time period needed for FDA approval so I'm really doing it for the learning experience. I'd love some help!