I don't know the specific answer to this as I didn't do it I just work with a lot of people who did, but as I understand it as a lab based science subject at university there is some numeracy. There will be quite a lot less of actual Maths than say a Physics degree (substantial) or Chemistry degree (a bit less than Physics, but many lab based calculations). From A-level choices to get into Pharmacy the typical student is not going to bed red hot on Maths anyway.
Pharmacy has calculations (a whole section) even on the preregistration exam sat after 4 years as an undergraduate + 1 year pre-reg.
I have studied with many people who didn't do Maths after GCSE and pretty much every single one of those has been stunned that 'Maths' has returned and is a part of their non-maths/physics science degree or particularly social science degrees in their 2nd or 3rd years. There are very few degrees that have no 'Maths' in, I'm just saying that for a wider picture. You're also not on your own, many universities have remedial maths courses for science students and there are other students/tutors who will be going through the same things.