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Flashcards in Oral (Solutions) Deck (13)
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1

Advantages of oral solutions: (3)

fast onset of action

dose uniformity

easy to swallow and easy to manufacture

2

Disadvantages of oral solutions: (3)

increased drug instability compared to in solid state

packaging costs higher

many drugs are poorly soluble in water

3

Oral solutions must be... (4)

stable

palatable

appropriate viscosity

at physiological pH

4

Most common solvent is water, why?

lack of toxicity

low cost

purified water is used - produced by distillation

5

What can be added to drugs to make them more water soluble?

co-solvents e.g. ethanol, glycerol

6

Excipients in solutions: (5)

antioxidants

flavouring, colouring agents

preservatives

viscosity enhancers

sweeteners

7

Factors effecting chemical degradation: (4)

high temp

pH

UV light

catalyst

8

How to enhance solution stability? (3)

package in containers that reduce light transmission

formulate at suitable pH

include excipients

9

How does pH affect solubility?

Ions are more water soluble than neutral molecules

alter pH can increase drug ionisation which increases drug solubility

10

Weakly acidic drugs are ionised when...

solvent pH increases

11

Lower solvent pH increases ionisation of...

weakly basic drugs

12

When are co-solvents used?

For non-ionic drugs where solubility cannot be adjusted by pH control

like dissolves like when choosing them

13

What are Cyclodextrins?

sugar molecules bound together in a ring

interior cavity - hydrophobic
exterior - hydrophillic

drug is releases from them and the free drug is absorbed increases aqueous solubility of drug