Formula

I cannot breastfeed due to preventive medications I need to get back on asap that are not safe for baby.... so with that I'm having a hard time choosing the right formula. I'm anti powder because I feel like it is never Ever mixed 100% no matter how you do it. Then dispite your efforts I feel it separates and causes issues for the baby!? HELP! The only formula I can find in concentrate is simalac!  Everything is powder or ready feed.... open to anything helpful please....