Some drugs must be administered by injection instead of being taken by mouth. Name a functional group in a drug molecule that could be broken down by the acid in the stomach.
The anti-cancer drug Taxol could be broken down if taken by mouth. Circle two bonds, each in a different functional group, that could be hydrolysed in the digestive system.
One method of protecting drug molecules taken by mouth is to trap them inside liposomes. These are artificially produced spheres made from phospholipids, each with an ionic phosphate ‘head’ and two hydrocarbon ‘tails’.
State in which area of the liposome, A, B or C, each of the following types of drug would be carried: a hydrophilic drug; a hydrophobic drug.
For the remaining position, A, B or C, explain why this would not be a suitable area for carrying a drug.
One way to transport drugs in the bloodstream is to join them by a chemical bond to a polymer. One such polymer is polyethylene glycol or PEG, $\text{HO}-(\text{CH}_2-\text{CH}_2-\text{O})_n-\text{H}$.
Where would a drug be attached to a molecule of PEG?
Suggest why a liposome can carry more drug molecules than a molecule of PEG.
State in which area of the liposome, A, B or C, a hydrophilic drug would be carried.
State in which area of the liposome, A, B or C, a hydrophobic drug would be carried.
Better-targeted delivery of drugs allows smaller amounts to be used, which brings significant advantages. Suggest two advantages of using smaller drug doses.