Or understanding the concept of polarity/solvency and how it would apply to pharmacokinetics (absorption, distribution, metabolism, elimination, blood brain barrier, etc........) The concept of polarity is introduced when? High school chem? Its hammered countless times in bio classes, chem classes, etc. It takes that much to master the idea so that it becomes simple common sense, not something you have to wrap your head around to answer a question. Thus by the time your in pharmacy school, you just would assume that a small highly non-polar drug would have a longer half life, higher Vd, and better penetration into the CNS because it just makes sense scientifically.
Pharmacy school would be impossible without having a background in chemistry and general biology, even if your not applying these basic principles, because the whole concept of how drugs work in the body and how the body affects the drug is based on chemistry and biology.