Venomous Weapon Fusion
(from Starfinder Core Rulebook)
A weapon with the venomous fusion gains the inject weapon special property. Only a single attack each day may benefit from this property, and you must announce before making an attack that it is an injection attack. Regardless of how many targets you can hit with a single attack from your weapon, only a single target of your choice is exposed to the drug, medicinal, or poison when you use the injection property in an attack. Only weapons that deal piercing or slashing damage can benefit from this fusion.