A number of common drugs are swallowed in forms like those shown. Some drugs are supplied as solutions. How would the rate of action of this form compare with P and Q? Explain your answer.
Explain which of the two forms, P or Q, would act fastest when taken by mouth.
Some drugs are broken down before they can be absorbed by the intestine. Suggest how the design of Q prevents this.
After an abdominal operation, drugs are often delivered using a ‘drip’ inserted into a blood vessel in the patient’s arm. Explain why this is more effective than taking painkillers by mouth.
Many common drugs are swallowed in forms similar to the ones shown (P and Q).
One molecule that has a range of uses in drug delivery is poly(ethylene glycol), or PEG. It is made from dihydroxyethane, $\text{HOCH}_2\text{CH}_2\text{OH}$. $2n\,\text{HOCH}_2\text{CH}_2\text{OH} \rightarrow \text{H}-(\text{OCH}_2\text{CH}_2\text{OCH}_2\text{CH}_2)_n-\text{OH} + (2n-1)\,\text{H}_2\text{O}$
What kind of reaction is this?
What kind of bonds would the PEG part of the molecule form with molecules in the body?
Suggest why attaching a PEG molecule to a drug molecule would lower the rate at which enzymes decompose the drug.
Drugs are often protein or polypeptide molecules. What reaction might take place in the breakdown of such a drug?