Fundamentals of drugs

Question 1

What is a solution?

Answer 1

A homogenous mixture of 2 or more substances

Question 2

What is the solute(s)?

Answer 2

The substance present in the smaller amounts

Question 3

What is the solvent?

Answer 3

The substance present in the larger amount

Question 4

What is solubility?

Answer 4

The number of parts of solvent (by volume) that will dissolve ONE PART of solute (by weight) [Can also be defined as the amount of solute that passes into solution]

Question 5

Describe an unsaturated solution

Answer 5

-More solute dissolves
-No solid remains in flask
-SOLUBILITY not reached yet

Question 6

Describe a saturated solution

Answer 6

-No more solute can dissolve
-Undissolved solid remains in flask
-Maximum limit of SOLUBILITY is reached

Question 7

Describe a supersaturated solution

Answer 7

-More solute than is normally possible
-Becomes unstable, crystals forming
-Maximum limit of solubility is exceeded

Question 8

What can be done to improve the solubility of poorly soluble drugs?

Answer 8

Adding water miscible solvents in which the compound is soluble (i.e a cosolvent)

Question 9

(Solubility enhancement) An ideal cosolvent should…(2)

Answer 9

1. Enhance the solubility of the drug
2. Be safe (non toxic)

Question 10

What is the most commonly used cosolvent (+ two others)

Answer 10

1. Ethanol
   -glycerol, glycol

Question 11

(Solubility enhancement) Why might you want to adjust the pH of a drug? (3 points)

Answer 11

-Most drugs are weak acids or weak bases (proportion of ionised to unionised fraction depends on the pH of the medium)
-We want drugs in their more ionised form as they are more water-soluble
-For weak acids to increase ionised fraction you will increase the pH but for weak bases you must lower the pH

Question 12

Three things to be wary of when manipulating the pH of solution.

Answer 12

1) Membrane irritation at extreme pH values
2) Formulation compatibilities
3) Formulation-container compatibility

Question 13

(Solubility enhancement)What is solubilisation?

Answer 13

The addition of surfactants (surface active agents) may be used as a strategy to solubilise poorly soluble drugs

Question 14

5 things a surfactant should be

Answer 14

1- Non-toxic
2- Miscible with the solvent system
3)Compatible with the other ingredients and the container
4) Free from bad odour
5) In case of oral administration- free from bad taste

Question 15

(solubility enhancement) What is chemical modification? + example

Answer 15

When a drug is chemically modified to produce a water soluble derivative (usually salt form)
- Sodium phosphate salt of hydrocortisone

Question 16

(Solubility enhancement) What is particle size control?

Answer 16

As particle size decreases, drug solubility increases.

Question 17

(Solubility enhancement) How does temperature affect solubility?

Answer 17

Solubility of the majority of drugs is endothermic and subsequently increasing the temperature enhances the solubility

Question 18

An orally administered drug must be able to…

Answer 18

1- Dissolve
2-Survive pHs (1.5-8.0)
3-Cross membranes
4-Survive liver metabolism
5-Survive intestinal bacteria
6-Avoid excretion by kidneys

Question 19

All pharmaceutical products should be… (3 points)

Answer 19

1- Efficacious
Optimum therapeutic level for specified period of time
2-Safe
Minimum or no side effects
3-Of good quality
The products should retain their properties during storage

Question 20

What is the primary purpose of medicines labelling and packaging?

Answer 20

The clear unambiguous identification of the medicine and the conditions for its safe use.

Question 21

Three common factors affecting all users of medicine may be…

Answer 21

1- Information = Certain items of information are vital for the safe use of the medicine
2-Format = The information must be presented in a legible manner that is easily understood by all those involved in the supply and use of the medicine
3- Style = There is potential for confusion between both similarity in drug names and similarity in medicines.

Question 22

Legal requirements of a label according to the MHRA (5)

Answer 22

1- Name of the medicine
2-Expression of strength (where relevant)
3-Route of administration
4- Posology
5- Warnings

Question 23

Some goals of packaging

Answer 23

1-Physical protection
2-Quality/Barrier protection
3-Identification
4-Marketing
5-Convenience
6-Security
7-Information transmission

Question 24

What is primary packaging? With examples

Answer 24

It is the material that first envelops the product and has direct contact with it. The smallest unit of distribution or use.
E.g.= Vials, caps, syringes

Question 25

What is secondary packaging? With examples

Answer 25

This is additional packaging material that improves the appearance of the product E.g. Outer wrappers on labels that do not make direct contact with the product

Question 26

What is tertiary packaging? With examples

Answer 26

Packaging used for bulk handling, warehouse storage and transport/shipping E.g.= Outer cartons, palletizedunit load.

Question 27

What are strip and blister packs?

Answer 27

Individual packaging of medicines, commonly used as unit dose packaging for pharmaceutical tablets/capsules/lozenges.

Question 28

What are the 2014 Recall Events?

Answer 28

*Defective container *Incorrect/missing package insert *Incorrect/missing lot # *Error on declared strength *label mix-up *Miscarton or mispackaged *Presence of undeclared colour additive *Misc