1. What is drug distribution and why is it an important factor in

pharmacokinetics?

- Answer: Drug distribution refers to the process by which a drug is

transported throughout the body. It is vital for achieving therapeutic

effects and understanding drug metabolism. The drug distribution process

determines how a drug is delivered to target tissues and organs.

2. Explain the term ‘plasma protein binding’ and its significance in drug

distribution.

- Answer: Plasma protein binding refers to the attachment of drugs to

plasma proteins, predominantly albumin. This binding affects the drug's

distribution and availability for action. Drugs bound to proteins have a

longer half-life and slower elimination, while unbound drugs are more

pharmacologically active.

3. How does drug distribution differ between highly lipophilic and highly

hydrophilic drugs?

- Answer: Highly lipophilic drugs easily penetrate cell membranes and

distribute extensively into tissues, leading to a larger volume of

distribution. On the other hand, highly hydrophilic drugs tend to remain in

the plasma rather than entering tissues, resulting in a smaller volume of

distribution.

4. Discuss the concept of blood-brain barrier and its impact on drug

distribution to the central nervous system.

- Answer: The blood-brain barrier acts as a protective mechanism,

preventing many drugs from freely entering the brain. Only drugs with