E.C.
Hi R. - I had the same problem with the regular Similac Sensitive. When I would try and mix it in the bottle it would clog the nipple so a friend recommended that I mix it in a larger shaker bottle then transfer it to the bottle. I used a 16 oz. Tupperware to do the mixing then just poured it in the bottle and didn’t have any issues. It was a different consistency then the RTF and my daughter rejected it at first, but I started to wean her off the ready to feed by subtracting 1 oz of her RTF bottle and adding 1 oz of the powder mix. It worked and by day 6 she was totally on the powder. Hope this helps.