BIO200H5 Lecture : bio200 lecture 3
Document Summary
Solubility: why study the interaction of drug molecules. Usually within the body and exposed to water. The membrane barriers to absorption/distribution are lipid (phospholipid). The sites of specific drug action: are often exposed to water (proteins, nucleic acids) A drug must be water soluble to reach them. But the body"s barriers are biological membranes: they are lipid. Drugs must also be lipid soluble to reach them - especially if they are taken by mouth: water is a polar solvent. The ideal drug: will have both water and lipid solubility. What makes molecules water soluble? van der waals radius of hydrogen = 1. 2 a van der waals radius of oxygen = 1. 4 a. Direction of dipole moment: examples of groups that tend to increase polarity: Aldehyde: what makes drugs lipid soluble? necessary. Non-polar groups are: examples of groups that tend to decrease polarity: I -br -cl -ch2 or ch3 -f (aromatic parent compound)
