Dump or keep?

Hi mommas! I give my LO a bottle of formula at night before bedtime (and breastfeed the rest of the time). Well I think she might be going through a growth spurt (currently 10 weeks old) and she has been extra fussy and tired the last couple of days.

Tonight she wanted nothing to do with the bottle and just wanted to nurse so I let her.

When I tried to offer the bottle at first she barely had the nipple if the bottle in her mouth and did not drink any of the formula- so is it safe to save that formula in the fridge and just use it sometime tomorrow within the 24 hr window since she didn't actually drink from it or do I need to toss it all since the nipple was in her mouth briefly?