I need help with reconstitution of medications. Is there a simple formula that someone is willing to share? Ratio and portion really Dont work well for me. Thanks so much in advance for your time and advice! Vancomyacin order- 1g the monograph states for reconstitution med available in 500mg vial:add 10 mls sterile water. final volume 10mls. Final concentration 50mg/ml. Pip/Taz order 2.275 monograph states available as combination of pipercillian 3g and tazobactrum 0.375g vial. dilute add 13 ns. final volume 15ml. final concentration 0.2 piperacillan/ml.