Emulsions

Question 0

What are the causes of coalescence?

Answer 0

increased d
decreased viscosity
not the right kind of surfactant (HLB to CMC too low)
too low concentration of surfactant

Question 1

Is coalescence reversible or irreversible?

Answer 1

irreversible

Question 2

What are the remedies for coalescence?

Answer 2

decrease d
increase viscosity
change surfactant (correct HLB or higher CMC)
increase concentration of surfactant
remedy is preventive

Question 3

Is creaming reversible or irreversible?

Answer 3

reversible

Question 4

What are the causes of creaming?

Answer 4

increased d
decreased viscosity
not the right kind of surfactant (HLB or CMC too low)
too low concentration of surfactant

Question 5

What are the remedies for creaming?

Answer 5

decrease d
increase viscosity
change surfactant (correct HLB or higher CMC)
increase concentration of surfactant
may rescue product

Question 6

What are the causes of excessive foaming?

Answer 6

too high concentration of surfactant

excessive stirring/mixing

Question 7

What are the remedies for excessive foaming?

Answer 7

decrease concentration of surfactant

avoid excessive stirring/mixing

Question 8

What are the causes of microbial growth in otherwise preserved emulsions?

Answer 8

only one phase is preserved
complexation of preservative with other ingredients (surfactants)
low concentration of preservative

Question 9

What are the remedies for microbial growth in otherwise preserved emulsions?

Answer 9

Add suitable preservative

increase concentration of preservative

Question 10

What is the cause of unpleasant taste of an oral emulsion?

Answer 10

inadequate masking of taste of drug
too low concentration of flavour/sweetener
too high concentration of surfactant

Question 11

What are the remedies for unpleasant taste of an oral emulsion?

Answer 11

increase flavour/sweetener or use different type

decrease concentration of surfactant