Joe,

I'm writing from the United States, and while I do not know the requirements
of the colleges of pharmacy in the UK, I can surmise that a BSc in chemistry
is a very good background to have if one is transferring into a school of
pharmacy.

When you say "conversion course", however, I assume you are expecting a
course of study, not just one course.
As one with a BA in biology, I was accepted into a pharmacy school as a
transfer student here in the US, back in 1973, and was granted two years of
pre-professional credit in science courses, plus credit for the required
courses (on this side of the pond) of economics and biochemistry taken as a
biology undergrad. I had to complete what we call the "professional years"
of study---3 years---at the college of pharmacy in which I was enrolled.
But, obviously, my biology degree, which included courses in general and
organic chemistry and the biochemistry and economics electives I took,
filled the bill.