introduction to medicinal products part 4

Question 1

what is an emulsion?

Answer 1

dispersion of liquids that are immiscible

Question 2

two types of emulsions?

Answer 2

water in oil w/o
oil in water o/w

Question 3

which emulsion is more preferred by patients and why?

Answer 3

oil in water because less greasy and can mask the unpleasant taste and smell

Question 4

why are o/w emulsions faster to absorb?

Answer 4

because drug is already dissolved

Question 5

what is important in making drugs in the form of an emulsion?

Answer 5

stability, if unstable then unexpected drug release which is dangerous

Question 6

what is cracking?

Answer 6

emulsion separating and no longer uniformaly distributed

Question 7

what are the causes of cracking?

Answer 7

temperature change, bacteria growth

Question 8

what form are ointments and pastes in?

Answer 8

semi-solid

Question 9

what are ointments and pastes for?

Answer 9

prevent trans epidermal water loss, helping with skin hydration

Question 10

difference between pastes and ointments?

Answer 10

pastes have a high concentration of drugs dispersed in it

Question 11

what determines the stability of emulsion?

Answer 11

emulsifier and oil used

Question 12

how does an emulsifier increase stability in an emuslion?

Answer 12

decreases the o/w interfacial tension

Question 13

examples of emulsifiers for pharmaceutical separation?

Answer 13

surfactants, proteins, polysaccharides, magnesium hydroxide

Question 14

what emulsifier effects the type of emulsion produced?

Answer 14

if its polar or non-polar

Question 15

how are emulsifier characteristics told apart?

Answer 15

HLB numbering system

Question 16

what is the structure of an amphiphile?

Answer 16

hydrophobic tail and hydrophilic head

Question 17

what is creaming?

Answer 17

flocculates and coalesce forms and rise to the surface

Question 18

why are SDS and CTAB hydrophilic?

Answer 18

their ionic charge

Question 19

examples of simple emuslifiers?

Answer 19

SDS, CTAB, Cetostearyl alcohol

Question 20

what are mixed emulsifiers?

Answer 20

charged and non-ionic, dense interfacial film

Question 21

why are single charged amphiphiles not used as emulsifiers?

Answer 21

repel
sparse interfacial film

Question 22

where are hydrophobic emulsifiers located on HLB?

Answer 22

near the bottom

Question 23

where are hydrophilic emulsifiers located on HLB?

Answer 23

near the top

Question 24

what is polyoxythylene?

Answer 24

a water soluble group

Question 25

what is polyoxythylene used for?

Answer 25

liquid vehicle, solid polymer, substituent (added to make molecules more hydrophilic

Question 26

what happens as the chain length of the polyoxythylene increases?

Answer 26

more vicious liquid to solid more hydrophilic

Question 27

what do all alkyl chains have in common?

Answer 27

searate C18

Question 28

what makes proteins aphiphiles?

Answer 28

hydrophobic region and hydrophilic regions

Question 29

how do proteins prevent coalescence?

Answer 29

'absorb at interfaces', forms surface network, barrier layer

Question 30

how are proteins used as stabilizing agents?

Answer 30

'bridge between droplets'

Question 30

why are proteins widely used in food products

Answer 30

good emulsifiers

Question 31

what are two natural emulsifiers in food?

Answer 31

milk, lecithin

Question 32

what kind of emulsion is milk?

Answer 32

'o/w stabilised by protein'

Question 33

what is the basis of many emulsifiers?

Answer 33

sorbitan

Question 34

why are sorbitan emulsifiers used?

Answer 34

cheap, four different OH groups so substituents can hang onto them, hydrocarbon substituents can be used to increases hydrophobicity, polyoxyethylene substituent can be added to increases hydrophilicity

Question 35

what is a HLB?

Answer 35

Hydrophile Lipophile Balance scale

Question 36

what is the diagram of polyoxythylene glycol?

Answer 36

slide 16