Part 3 Flashcards

1
Q

name the general components of aerosols

A

product concentrate + propellant

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2
Q

explain what the “product concentrate” of aerosols contains

A

it is a solution of:

-active ingredient
-antioxidants
-surface-active agents
-solvents

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3
Q

what does it mean if something has high vapor pressure

A

it is VOLATILE – meaning it evaporates easily

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4
Q

what are the most common liquefied gas propellants? are they used much anymore?

A

CFC (chlorofluoro carbons)
not used as much bc they destroy the ozone

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5
Q

if temperature is ____ than vapor pressure, the propellant becomes a gas

what does this mean about the vapor pressure of the propellants used in aerosols?

A

HIGHER

therefore, the propellants used in aerosols all have vapor pressures BELOW room temp (25 degrees celsius)

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6
Q

what is the concern with liquid density of propellants used in aerosols?

A

we want to know if their density is higher or lower than water

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7
Q

true or false

at room temperature, propellants are gasses

A

true

this is because they have vapor pressures that are lower than room temp

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8
Q

name the kinds of aerosol systems

A

-two phase systems
-three phase systems
-compressed gas systems

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9
Q

which are more popular - two phase aerosol systems or three phase systems?

A

two phase are more popular

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10
Q

explain the difference between the 3 aerosol systems

A

two phase systems = product concentrate + miscible liquid propellant + gas propellant

three phase system = liquid propellant that is NOT miscible with the product concentrate + gas propellant

compressed gas system = uses compressed gas (PSI)

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11
Q

name 3 types of containers used for aerosols

which is most popular?

A

glass (could be coated with plastic)
metal
plastics

metal is mot frequently used (aluminum - lightweight)

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12
Q

why are plastics not usually a suitable choice for aerosol containers?

A

not very good for maintaining pressure because it leaks out through pores from polymers

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13
Q

for which type of system must it be shaken before use?

A

3 phase system

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14
Q

explain the concept of three phase systems

A

the density of the immiscible liquid propellant is lower than the product concentrate so the liquid propellant remains on the top.

this means it won’t all get sprayed out. the only propellant that will get sprayed out is the very little bit that dissolves in the product concentrate

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15
Q

name 2 methods of filling aerosols

A

cold filling – both the product concentrate and propellant must be cooled. once returned to room temp, the liquid propellant will evaporate and create pressure (only in manufacturing)

pressure filling - can only be done in manufacturing. fit all liquid propellant back in under pressure when you run out

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16
Q

name 4 ways in which the filled aerosol containers are tested

A

leaking
valve assembly
particle size distribution
dose (for MDIs)

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17
Q

what serves as the reservoir to replenish the gas propellant

A

the liquid propellant. want to maintain equilibrium so when the bottle is sprayed and gas propellant leaves, some liquid evaporates to maintain equilibrium

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18
Q

name 4 major factors via aerosol inhalation

A

-physical factors (2 or 3 phase?)
-pattern of inhalation
-delivery device used (spacer)
-status of the lungs (what volume can the lungs hold? penetration/deposition?)

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19
Q

give an example of a dry powder inhaler.

A

SPINHALER turbo inhaler

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20
Q

true or false

SPINHALER turbo inhaler is a liquid aerosol that does not contain a canister

A

FALSE

solid aerosol. does not contain a canister

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21
Q

name an advantage of SPINHALER turbo inhaler

A

it’s a solid aerosol. therefore, we are not inhaling liquid propellant which is potentially bad for our bodies

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22
Q

generic for Intal

A

Cromolyn Sodium

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23
Q

name the dosage forms available for Intal

A

capsules (for inhalation)
nebulizer solution
metered dose inhaler

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24
Q

true or false

there are 3 Intal products available

A

true
capsules for inhalation
nebulizer solution
metered dose inhaler

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25
Q

what is the use of Intal

A

ANTIASTHMATIC

for prevention of exercise induced bronchospasms

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26
Q

define rheology

A

the study of flow. involves the viscosity characteristics of powders, fluids, and semisolids

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27
Q

name the types of flow

A

newtonian flow
non-newtonian flow

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28
Q

differentiate between the types of flow

A

Newtonian flow – CONSTANT VISCOSITY, regardless of the shear rates applies

non-newtonian flow - change in viscosity characteristics with increasing shear rates

29
Q

non-newtonian flow includes…..

A

plastic, pseudoplastic, and dilatant flow

30
Q

true or false

for non-newtonian flow, the viscosity can increase or decrease with increasing speed

A

TRUE

31
Q

true or false

NEWTONIAN FLOW FOLLOWS NEWTONIAN’S LAW

A

true

32
Q

define viscosity

A

an expression of the resistance to flow of a liquid system under an applied stress

33
Q

what is “Poise”

A

the unit of viscosity.

the shearing force required to produce a velocity of 1cm/sec between 2 parallel planes of liquid

34
Q

1cp =___poise

A

0.01 poise

35
Q

explain what 1 centipoise is

A

1 centipoise = each 1 cm squared in area and separated by a distance of 1cm

36
Q

give the USP/NF definition of Kinematic viscosity

A

the absolute viscosity divided by the density of the liquid AT A DEFINITE TEMPERATURE

37
Q

what is the unit of kinematic viscosity

A

stoke

38
Q

give the formula for kinematic viscosity

A

n’/p

p = density
n’ = absolute viscosity

39
Q

at a constant _____, viscosity will NOT CHANGE

A

constant temperature

40
Q

what is the simplest and cheapest method to measure viscosity ?
name the instrument

A

capillary viscometer

Ostwald viscometer

41
Q

besides the capillary viscometer (Ostwald viscometer), name 4 other methods of measuring viscosity

A

falling sphere viscometer (Hoeppler viscometer)
cup and bob viscometer
cone and plate viscometer
brookfield viscometer

42
Q

what is the absolute viscosity of water at 20 degrees celsius ?

A

1.0019 (assume 1)

43
Q

name 6 newtonian liquids

A

castor oil
chloroform
ethyl alcohol
glycerin 93%
olive oil
water

44
Q

rank the 6 newtonian liquids in order of increasing viscosity

A

highest - castor oil
glycerin (93%)
olive oil
ethyl alcohol
water
lowest - chloroform

45
Q

what does the modified arrhenius equation measure

A

absolute viscosity using arrhenius constant, activation energy to intimate flow, gas constant, absolute temp

46
Q

as the temperature of glycerin increases, what happens to viscosity

A

it decreases

47
Q

explain what non newtonian flow is

A

change in viscosity = increasing shear rate

48
Q

what are the types of non newtonian flow

A

plastic flow
pseudoplastic flow
dilatant flow

49
Q

what pharmaceutical dosage forms are part of non newtonian flow?

A

colloidal solutions
emulsions
liquid suspensions
ointments

50
Q

in plastic flow, what are the substances called?

A

Bingham bodies

51
Q

explain plastic flow

A

does not begin until a shearing stress corresponding to a certain yield value (f) is exceeded

below (f), the materials are ELASTIC

52
Q

in plastic flow, as viscosity _____ to a certain amount, shear rate remains relatively constant with further ___ in viscosity

A

decreases

53
Q

in pseudoplastic flow, what are the substances called?

A

“shear-thinning” systems

54
Q

what is the yield value in pseudoplastic flow

A

no yield value

55
Q

in dilatant flow, what are the substances called?

A

shear thickening systems

56
Q

in dilatant flow, what happens with increasing shear rate?

A

the volume of dilatant materials increases and the viscosity of them also increases

57
Q

dilatant flow is the inverse of what flow?

A

pseudoplastic

58
Q

besides plastic, pseudoplastic, and dilatant, name 3 other non newtonian flows

A

thixotropic
antithixotropic
rheoplastic

59
Q

name 4 pharmaceutical areas in which rheology is significant

A

fluids
quasisolids (semisolids)
solids
processing

60
Q

explain how the rheology of solids is a significant consideration in pharmaceutics

A

-the flow of powders from the hoppers and into the dye cavities in tablet/capsule during encapsulation

-packagability of powdered or granular solids

61
Q

explain how “processing” rheology needs to be considered

A

-the production capacity of the equipment
-the processing efficiency

62
Q

explain how the rheology of quasisolids (semisolids) needs to be considered

A

-spreading and adherence on the skin
-removal from jars or extrusion from tubes
-capacity of solids to mix wiht miscible liquids
-release of the drug from the base

63
Q

explain how the rheology of fluids needs to be considered

A

-mixing
-particle size reduction of dispersed systems with shear
-passage through orifices (including pouring, packaging, and passage thorugh hypodermic needles)
-fluid transfer (inc pumping and flowing through pipes)
-physical stability of disperse systems

64
Q

explain newtonians law of flow

A

force/amount of ointment = viscosity coefficient (n) * dv/dr

dv = difference in velocity
dr = difference of distance in dv

65
Q

in Newtonian’s law of flow, what does it mean if dv is low?

A

the ointment is very viscous

66
Q

what is F/A

A

force/area
represents shearing stress (F). given in newtonian’s law of flow

67
Q

according to Newtonian’s law……..

A

the rate of shear should be directly proportional to the shearing stress

68
Q
A