Phar 321 - Co-Solvents And Excipients In Pharmaceutical Solutions

Front 1

Which type of water is preferred and most commonly used as a vehicle for solutions for oral administration?

Back 1

Purified Water USP (low cost/ low toxicity)

*Solid residue is <1g/100ml of evaporated sample

Front 2

Purpose of aromatic/ volatile oils in water?

Back 2

To mask the taste or smell of an active pharmaceutical ingredient.

Example: peppermint water

Front 3

How are alcohols (e.g. ethanol, glycerin) used in solutions?

Back 3

Rarely used on their own. Usually a co-solvent of water.

Front 4

How are non-polar solvents (e.g. vegetable oil, triglycerides) used?

Back 4

For water insoluble drugs.

Front 5

What are the 4 methods to increase the solubility of poorly soluble drugs?

Back 5

1. Use of buffers

2. Co-solvents

3. Surfactants

4. Complexation

Front 6

How do buffers improve the solubility of drugs?

Back 6

Buffers adjust and maintain the pH of the solution to keep the drug in its ionized state.

Acidic drugs are formulated under basic conditions, and vice versa for basic drugs.

Front 7

What are common buffers used?

Back 7

1. Acetates (acetic acid and sodium acetate)

2. Citrates (citric acid and sodium citrate)

3. Phosphates (sodium phosphate and disodium phosphate)

Front 8

What is the purpose of a co-solvent?

Back 8

Help improve solubility of the unionized component of ionizable drugs.

Water miscible organic solvents reduce the polarity of the solvent system.

Front 9

Name some common co-solvents: (4)

Back 9

1. Alcohol USP (~95% v/v ethanol)
2. Polyethylene glycol (PEG)
3. Propylene glycol
4. Glycerine or glycerol

Front 10

How are surfactants used for poorly soluble drugs?

Back 10

They are compounds that have both hydrophilic and hydrophobic tails that form micelles.

Above the critical micelle concentration, non-polar drugs can partition into micelles.

Front 11

Give examples of a surfactant that is:

1. Non-ionic

2. Anionic

3. Cationic

4. Zwitterionic

Back 11

1. Polyethylene glycol (PEG)

2. Sodium dodecyl sulfate

3. Trialkylammonium

4. Glycine

Front 12

What is complexation, and how is it used to increase the solubility of poorly soluble drugs?

Back 12

Complexation: two or more molecules form a non-covalent complex that has a higher solubility than the drug itself. The drug can interact with the complex to limit exposure to water.

Front 13

What are the types of complexes available? (2)

Back 13

1. Stacking complexes - association of non-polar areas of the drug and complex agent.

2. Inclusion complexes - insertion of the drug molecule into a cavity formed by the complex (e.g. steroid into cyclodextrin)

Front 14

Which flavours do you use to mask salty solutions? (6)

Back 14

1. Butterscotch

2. Apricot

3. Peach

4. Vanilla

5. Mint

6. Maple

Front 15

Which flavours do you use to mask bitter solutions? (3)

Back 15

1. Cherry

2. Mint

3. Anise

Front 16

Which flavours do you use to mask sweet solutions? (2)

Back 16

1. Vanilla

2. Fuit/ berry

Front 17

Which flavours do you use to mask sour solutions? (3)

Back 17

1. Citrus flavours
2. Raspberry
3. Licorice root

Front 18

Which flavour adjuncts are used to desensitize taste receptors? (2)

Back 18

1. Methanol

2. Chloroform

Front 19

What happened to the wooden car with the wooden wheels and the wooden engine?

Back 19

It wooden go!

Front 20

Which sweeteners are natural and artificial?

1. Saccrine

2. Sorbital

3. Sucrose

5. Aspartame

6. Stevia

Back 20

1. Artificial

2. Natural

3. Natural

4. Artificial

5. Natural

Front 21

How do you remove the bitter/ metallic after taste from artificial sweeteners?

Back 21

Add a small amount of natural sweetener to mask the taste.

Front 22

Which dye colour do you use for mint-flavoured solutions?

Back 22

Green

Front 23

What is the purpose of viscosity enhancing agents?

Back 23

Increases ease of handling, palatability, and helps to ensure accurate measurement of the dispensed volume.

Front 24

Which viscosity enhancing agents are neutral polymers and ionic polymers?

1. Hydroxyethylcellulose
2. Sodium alginate
3. Polyvinylpyrrolidine (PVP)
4. Sodium carboxymethylcellulose

Back 24

1. Neutral
2. Ionic
3. Neutral
4. Ionic

Front 25

Define: API

Back 25

Active pharmaceutical ingredient

Front 26

What is the purpose of antioxidants?

Back 26

Drugs are prone to chemical degradation by oxidation. Antioxidants enhance stability of drug, preservatives, colorants and solvents.

Antioxidants get oxidized rather than the drug, so the concentration will decrease over time.

Front 27

Which antioxidants are water soluble?

1. Ascorbic acid

2. Butylated hydroxytoluene

3. Sodium sulfate

4. Sodium formaldehyde sulphoxylate

5. Propyl gallate

Back 27

1, 3, 4

Front 28

What is the purpose of chelators?

Back 28

Chelators form complexes with heavy-metal ions. These ions can degrade API, so chelators increase shelf life.

Ex. EDTA, Citric acid

Front 29

What is the purpose of preservatives?

Back 29

They inhibit the growth of microorganisms.

Front 30

What are ideal qualities of preservatives?

Back 30

1. Broad spectrum antimicrobial activity

2. Good aqueous solubility and partitioning

3. Chemical and physical stability

4. Low toxicity

Front 31

MOA of acidic preservatives:

Back 31

The unionized form of preservatives can penetrate microbial membranes. The preservative can ionize inside organism to acid, denature proteins, and inhibit growth in cytoplasm.

*concentration must be > minimum inhibitory concentration*

Acidic preservatives work better in acidic environments.

Front 32

What does a shark like to eat with peanut butter?

Back 32

Jellyfish!

Front 33

MOA of parabens (preservative):

Back 33

Denatures proteins.

Ex: alkyl esters of parahydroxybenzoic acid

Front 34

MOA of chlorinated phenolic compounds (preservative):

Back 34

Oxidation of enzymes, lytic and denaturation of membranes

Front 35

MOA of alcohol (preservative):

Back 35

Lytic and denaturation action on membranes

Front 36

MOA of mercurials (preservative)

Back 36

Denatures enzymes by combining with thiol (-SH) group.

Front 37

MOA and purpose of anti-foaming agents?

Back 37

With foam, not all of the API is within the solution (changes concentration)

Anti-foaming agents decrease surface tension and increase cohesive binding of liquid phase.

Ex. simethicone

Front 38

What is the purpose of adding cyclodextrin to an oral solution?

Back 38

1. Enhances solubility of API

2. Increases bioavailability of API

3. Improves chemical, physical and thermal stability

4. Reduces GI irritation

5. Prevents compatibility issues with other APIs/ excipients

6. Masks odor/ taste