My little girl is on it now and has been for about 4 months now. It's down to what your prescription says. Our Dr prescribed 3200g at a time and that gives us 4 big tins each time. I just reorder the prescription as soon as open the last tin. Not sure on the premade bottles as we've never looked into it or needed them..
My son has been on it for the last 5 months. They don’t do pre-made bottles unfortunately. Although Aptamil does seem to stock them in other European countries, I just couldn’t figure out how to get it in the UK. The amount the doctor prescribes is based on baby’s age and they said to call the pharmacy when you have about a week’s worth left to get more in. For us that means when we have about x4 400g tubs left or x2 800g tubs depending on what size they gave us. It’s super straightforward and they don’t ask many questions so you could definitely call and ask for more when you have a week and a half’s supply left to make sure you’re always well stocked x
I used to get 6 tins and now get 5. Make sure to ask them to switch to pepti 2 when he’s 6 months as that has more of what the baby needs during 6 months and afterwards
My eldest child was prescribed it, we used to get 6 tubs per month which seemed to last us well. They didn't do any pre-made bottles when we used it but that was around 7 years ago now