The 58-year-old guitarist has been busy working on Orgy Of The Damned, a record of mostly blues tracks featuring a string of guest vocalists.
He said he did not want to "drag" his Guns N' Roses bandmate Axl Rose into appearing on the album because their group was busy with the long-awaited follow-up to 2008's Chinese Democracy, which Slash didn't appear on.
"It was my own side thing, so I wasn't dragging my own guys in," Slash told the Daily Star Sunday newspaper's Wired column, explaining why Rose and his The Conspirators collaborator Myles Kennedy don't feature on his new album.
"Guns N' Roses are trying to make their own record and I'm working with them in that capacity but this didn't involve anyone else."
In December, the group released Perhaps, backed by The General, which were both recorded around the same time as Chinese Democracy - and 2021 releases Absurd and Hard Skool.
The notorious record was delayed for years and held up by legal issues, while Slash, bassist Duff McKagan and drummer Matt Sorum quit the group, and only frontman Rose and keyboardist Dizzy Reed remained.
Slash has previously teased more new music from the hard rock band.
However, he later admitted he and his bandmates hadn't penned any new material since reuniting.
"As far as new Guns is concerned; we haven't even gotten to that point of really in earnest sitting down and writing," Slash said in October 2021.
"We've been doing a lot of material that's been sort of sitting around for a while.
"So that will be a whole focused endeavour unto itself."
The band reunited with original members Slash and McKagan for the 2016 Not in This Lifetime ... Tour.
Rose, Slash and McKagan's last studio album was the 1993 covers record The Spaghetti Incident?