There are two Japanese language items that have both been translated as 'Tranquilizer'. The first is 麻酔針 / ますいばり [masuibari], meaning 'anesthetic needle' in Japanese. The second is 鎮静剤 [chinseizai], which translates as 'tranquilizer' or 'sedative' in Japanese.
Final Fantasy III

Buy: - (sell: ? gil)
Drop: Abaia, Acheron, Balloon, Bomb, Fachan, Giant Rat, Grenade, Griffon, Haokah, Kyklops, Lamia, Lemur, Magician, Oceanus, Rock Gargoyle, Sleipnir, Tangie, Thor, Vulcan
Steal: Abaia, Acheron, Balloon, Bomb, Fachan, Grenade, Haokah, Kyklops, Magician, Oceanus, Rock Gargoyle, Sleipnir, Thor, Vulcan
Treasure: Cave of Shadows
Type: Consumable
Effect: inflicts Paralysis
Other: 麻酔針 in Japanese
Final Fantasy VII

Buy: 100 gil (sell: ? gil)
Shop: Bone Village, Cosmo Canyon, Costa Del Sol, Fort Condor, Gold Saucer, Gongaga, Junon, Kalm, North Corel, Mideel, North Corel, Rocket Town, Sector 7, Temple of the Ancients, Wall Market, Wutai
Drop: various
Effect: cures Fury, might inflict Sadness
Other: 鎮静剤 in Japanese
Category: Item