Sunderland saw five players join the club in January.
Jan Kirchhoff, Lamine Kone, Wahbi Khazri, Steve Harper and Dame N'Doye all arrived at the Stadium of Light, while the club were reported to be close to signing Mathieu Debuchy on loan from Arsenal.
Allardyce said: “I think, in general, we were happy with the business we did.
“Only time will tell, but we think we’ve increased the quality of the squad and taken a calculated risk."
As for not being able to get another deal over the line: “We were close in the last couple of days, but couldn’t pull it off for a number of reasons.
“Some clubs had players who they were going to let leave, but they changed their minds because of injuries.
“Some of the players we looked at got injured themselves.
“And some of the players we asked about didn’t want to come.”
A couple of them impressed during the 1-0 defeat to Manchester City, so the immediate signs suggest there has been some quality added at the Stadium of Light.
Ideally it seems they would've liked a new right-back but they have strengthen to a degree in pretty much every area of the field and will feel if they repeat the kind of performances they showed against Manchester City then they'll find themselves in a decent position at the end of the season.