Lecture 2

Question 1

What are the two main components of all medicines?

Answer 1

1. Active Pharmaceutical Ingredients (APIs) – therapeutic agents
2. Excipients – inactive ingredients that assist with delivery

Question 2

What is pharmaceutical formulation?

Answer 2

The process of combining various chemicals with the API to form a final medicinal product.

Question 3

What are dosage forms and what is their function?

Answer 3

Dosage forms define the route of administration and may vary for the same API, depending on the medical condition and treatment requirements.
To achieve a predictable therapeutic response, ensure chemical and physical stability, and allow for large-scale manufacture.

Question 4

Give an example of an API with various dosage forms and strengths.

Answer 4

Paracetamol, which is available in tablets, capsules, and liquids to meet different user needs.

Question 5

What is bioavailability?

Answer 5

The extent to which an API becomes completely available to its intended biological destination.

Question 6

Describe the typical journey of an oral solution

Answer 6

Stomach -> Small intestine -> Absorption -> Liver -> Metabolism -> Blood -> Target -> Kidney -> Excretion

Question 7

What is codeine, and how does its onset of action vary?

Answer 7

Codeine is an analgesic that is converted into morphine in the brain, and its onset of action depends on the route of administration.

Question 8

In what state are most APIs during formulation and absorption?

Answer 8

Solid state during formulation, liquid state for absorption.

Question 9

What are some key chemical properties in dosage form development?

Answer 9

pKa, permeability, and solubility, with poor solubility being a limiting factor in drug development.

Question 10

What is the Biopharmaceutical Classification System (BCS)?

Answer 10

A system that classifies drugs based on their solubility and permeability.

Question 11

Name two techniques to enhance solubility

Answer 11

1. Chemical modifications (e.g., forming salts or complexes)
2. Physical modifications (e.g., size reduction)

Question 12

What is crystallization? Give an example of an API with different crystalline forms.

Answer 12

A separation and purification process where crystals are formed by inducing a change from the liquid to the solid state
Insulin, which exists in forms with varying durations of action.

Question 13

What is polymorphism in drug substances? Give an example of an API that exhibits polymorphism.

Answer 13

The ability of a drug to exist in more than one crystalline form, with different physical properties affecting bioavailability. Oxytetracycline

Question 14

What is the difference between salts and cocrystals in drug development?

Answer 14

Salts form when an acid reacts with a base, while cocrystals form between neutral APIs. Both are important considerations in drug development.

Question 15

Why are different routes of administration used?

Answer 15

Due to the physical and chemical properties of the API, desired site of action, rapidity and accuracy of action, and patient condition.

Question 16

What are the advantages and limitations of the oral route of administration?

Answer 16

Advantages: Common and convenient
Limitations: Low and unpredictable absorption in the gastrointestinal tract

Question 17

What is the parenteral route of administration?

Answer 17

Injecting a drug as a liquid into tissue or the bloodstream, offering rapid absorption but requiring sterile procedures and can be painful.

Question 18

What is the topical route of administration?

Answer 18

Applying a drug to the surface of the skin or mucous membranes for a local effect.

Question 19

What are transdermal patches?

Answer 19

A type of topical delivery system that allows for slow and continuous drug absorption through the skin.

Question 20

What is the respiratory route of administration?

Answer 20

Administering drugs through inhalation, where they are absorbed via the lungs.

Question 21

What is the sublingual/buccal route of administration?

Answer 21

Placing a drug under the tongue or between the gums and cheek for rapid absorption into the bloodstream, bypassing first-pass metabolism.

Question 22

What is the rectal route of administration?

Answer 22

Administering drugs via the rectum, which avoids some first-pass metabolism and is used when oral administration isn’t feasible.