Just started my 8 week old on gaviscon infant & wondering once you have made it up (I breastfeed so put it in a bottle) and wondered how long it lasts once it's made up as I'm having trouble giving it to my daughter through the bottle as she's not keen on the bottle or the taste of the gaviscon I'm assuming. So wondering if say it takes me 20 mins to give it all to her would that be okay?