Most infant formulas are made from soy products which are kitniyot. Since kitniyot does not apply to infants most formulas may be used on Passover. For a list of acceptable formulas please visit oukosher.org/passover/articles/baby-formula/. Please note that care should be taken to keep bottles, nipples and formula away from the general kitchen area. Any mixing or washing should be done elsewhere, such as in the bathroom sink.