The Arbazan were a sentient, humanoid species, whose homeworld was a member of the United Federation of Planets by 2369.
Bolian Ambassador Vadosia mocked them as a "sexually repressed" species. (DS9: "The Forsaken")
Taxco's Arbazan prosthetics and costume were a reuse of Bhavani's Barzan prosthetics and costume from TNG: "The Price", except for the Barzan breather.
According to StarTrek.com, the Arbazan were native to the planet Arbaza. 
According to Star Trek: Star Charts ("United Federation of Planets I") and Stellar Cartography: The Starfleet Reference Library ("Federation Historical Highlights, 2161-2385"), there was a star system named Arbazan, which might be the home system of this species, in the Alpha Quadrant. This system's primary was a M-class star. In 2385, this was an UFP system.