Solutions Flashcards
Type of solution: Alloys like brass, bronze, etc.
Solid-solid
Type of solution of the solution of sugar, salt, etc. in water
solid-liquid
Type of solution of the Sublimation of substances like iodine, camphor, etc. into the air
solid-gas
Type of solution of substances like iodine, camphor, etc. into the air
Solid-gas
Type of solution for the hydrated salts, mercury in amalgated zinc, etc
Liquid-solid
Type of solution for Alcohol in water, benzene in toluene
Illiquid-liquid
Type of solution for aerosol, water vapour in the air
liquid-gas
type of solution for hydrogen absorved in palladium
Gas-solid
Type of solution for aerated drinks
gas-liquid
Type of solution for a mixture of gases
gas-gas
Solutes are inseparable from the mixture and do not sediment. It is stable
Solution
its components cannot be separated using filtration
Solution
The major consideration in assessing the acceptability of a suspension
Redispersibility
two most common basic evaluative procedures
- Measurement of the sedimentation volume
- Ease of redispersion
simple ratio of the height of sediment to initial height of the initial volume
Sedimentation volume
particle size of the suspension is about 2-5 micrometer
brownian movement
Used to assess suspension for stress testing for stability testing result in increase of particle growth and may indicate future state after long storage
Freeze-thaw cycling technique
apparatus used in sedimentation
Andreasen apparatus
Coulter counter apparatus
allows the observer to view the actual particles
Microscopic method
Number of hours for freezing and thawing
Freezing: 18 hours (freezer)
thawing: 4-6 hours (room temp)
A clear, homogeneous liquid dosage form that
contains one or more chemical substances dissolved in
a solvent or mixture of mutually miscible solvents.
Solution
The component that dissolves the other
component.
Solvent
-It is a homogeneous mixture
Solution
The component(s) that is/are dissolved in the
solvent.
Solute
particles are too tiny and have a diameter less than
1 nm.
Solution
particles are not visible to naked eyes
Solution
Particles don’t scatter a beam of light passing through
it and hence the path of the light is not visible.
Solution
Solutes are inseparable from the mixture and do not
sediment.
Solution
Visual inspection for the presence of gross
floating or particulate matter.
Solution
Observes clarity, particulate matter, color
Appearance
detection of the presence of degradation - assay of potency
Chemical stability
determined by the use of viscometer
viscosity
determined spectrophotometrically at a particular wavelength.
color
subjective evaluation by the formulator, taste panel
odor and taste
A liquid dosage form that consists of solid particles
dispersed throughout a liquid phase.
SUSPENSION
a coarse
dispersion in which internal phase (therapeutically
active ingredient)is dispersed uniformly
throughout the external phase.
SUSPENSION
The internal phase consisting of insoluble solid particles having a range of size(0.5 to 5 microns) which is maintained uniformly through out the
suspending vehicle with aid of single or
combination of suspending agent
SUSPENSION
The external phase (suspending medium) is
generally aqueous in some instance, may be an
organic or oily liquid for non oral use.
Suspension
reasons for the formulation of a pharmaceutical
suspension:
- when the drug is insoluble in the delivery
vehicle. - To mask the bitter taste of the drug.
- To increase drug stability. - To achieve controlled/sustained drug release.
QUALITY CONTROL TEST FOR SUSPENSION
Sedimentation volume
Test for Redispersibility
Particulate Size Measurement
Viscosity (rheological/property)
Zeta Potential determination
Temperature and Gravitational stress
major consideration in
assessing the acceptability of a suspension
Redispersibility
the simple ratio of
the height of sediment to initial height of the
initial suspension.
sedimentation volume
Sedimentation Volume Formula
Vs= Vu/Vo x 100
ideal
suspension
Vs- (approximate) 1
The sedimentation volume gives only a quantitative
account of flocculation. T or F
False. Qualitative
the amount of force necessary to redisperse the particles
Test for Redispersibility
No settling occurring.
Brownian movement
Lower the no. of revolution or shorter time for redispersion
Faster dispersibility.
Using of microscope with micrometer eyepiece.
Particulate Size Measurement
Rapid processing of photo micrographs is enhanced
by attaching what to the piece of monomolecular microscope.
Polaroid camera
used to assess
suspension for stress testing for stability testing result in increase of particle growth and may indicate future
state after long storage.
freeze-thaw cycling technique
Particle Size and Size Distribution is performed by optical microscopy, sedimentation
by using these instruments
Andreasen apparatus and Coulter counter
apparatus.
allows the observer to view the actual particles. The sedimentation method yields a
particle size relative to the rate at which particles
settle through a suspending medium.
Microscopic method
conducted by placing the sample
in a freezer for 18 hours followed by thawing at
room temperature for 4 to 6 hours.
FREEZE- THAW TEST
conducted to determine the tendency
to crystallize
FREEZE- THAW TEST
help in determining the
settling behaviour of the suspension.
Rheological methods
with variable shear stress
control can be used for evaluating viscosity of
suspensions.
Brookefield viscometer
It consists of T-bar spindle which is lowered into the
suspension and the dial reading is noted which is a
measure of resistance the spindle meets at various
levels in the suspension.
Brookefield viscometer
Repulsive forces between particles
Zeta Potential Determination
expose in high
temperature, then perform any of 1-5 tests.
Temperature stress test
using centrifuge.
Gravitational stress test-
The formulation exhibiting thixotropic properties a rise in temperature would change the properties.
Stability Testing
The valid temperature data could be obtained that will be useful in the estimation of the physical stability of a product at normal storage conditions.
Stability Testing
two phase dispersion of liquids that are normally not miscible.
EMULSION
a-aka internal phase
dispersed phase
b-external phase
dispersion medium
viscid, multiphase systems in which
one or more liquids are dispersed throughout another immiscible liquid in the form of small droplets.
Emulsions
When oil is the dispersed phase and an aqueous
solution is the continuous phase
oil-in-water emulsion
When water or an aqueous solution is the
dispersed phase and oil or oleaginous material is
the continuous phase
water-in-oil emulsion
stabilized by emulsifying agents that prevent coalescence, the merging of small droplets into larger droplets, and, ultimately, into a single separated phase.
Emulsions
act by concentrating at the interface between the
immiscible liquids, thereby providing a physical barrier that reduces the tendency for coalescence.
Emulsifying agents
reduce the interfacial tension between the phases, facilitating the formation of small droplets upon mixing
Surfactants
type of emulsions which
the continuous phase is usually hydrophobic materials
such as oil and the dispersed phase is water.
Water-In-Oil Emulsions (W/O)
W/O emulsions three substances
a solvent,
a surfactant, and
water
emulsion in which the
oil exists as the dispersed phase and water as the
dispersion medium or continuous phase.
Oil-In-Water Emulsions (O/W)
stabilized using a combination of hydrophilic and
hydrophobic surfactants.
Multiple Emulsions
more complex and contain very small droplets suspended in larger droplets that
are also dispersed in a continuous phase.
Multiple Emulsions
consist of water droplets entrapped in bigger oil droplets that are sequentially suspended in a continuous water phase
W/O/W
emulsion is diluted either with oil or water
Dilution Test
Phase inversion in emulsion is determined
through what test
dye solubility test
Sudan red- oil soluble dye result is?
w/o
Amaranth green- water soluble dye result is?
o/w
When a filter paper soaked in cobalt chloride
solution is added to an emulsion and dried, it
turns from blue to pink, indicating that the
emulsion is o/w type.
Cobalt Chloride Test
If an emulsion on exposure to ultra-violet
radiations shows continuous fluorescence under microscope, then it is w/o type and if it shows
only spotty fluorescence, then it is oil in o/w type.
Fluorescence Test
emulsion exposed to ultra-violet radiations showing CONTINOUS fluorescence under microscope
w/o
emulsion exposed to ultra-violet radiations showing SPOTTY fluorescence under microscope
o/w
They are added to disperse solids in continuous
liquid phase.
Wetting agents
They are added to floc the drug particles.
Flocculating agents
They are added to increase the viscosity of
suspension.
Thickeners
They are added to stabilize the suspension to a desired pH range.
Buffers and pH adjusting agents
They are added to stabilize the suspension to a desired pH range
Buffers and pH adjusting agents
They are added to adjust osmotic pressure
comparable to biological fluid.
Osmotic agents
They are added to impart desired color to
suspension and improve elegance
Coloring agents
They are added to prevent microbial growth.
Preservatives
They are added to construct structure of the final
suspension.
External liquid vehicle
Important from a processing
aspect to minimize segregation.
Viscosity
Problems in the packaging of oral liquids
potency (fill) of unit dose products,
accurate calibration of measuring devices such as
droppers
Glass used in packaging of non sterile suspensions.
soda lime and borosilicate glass
doesn’t allow U.V light to pass through.
Amber glass
Plastics used in packaging due to the negative aspects of glass, plastic
material significantly use of plastic as packaging
material for sterile as well as non-sterile
pharmaceutical suspension increased.
Polyethylene, PVC, polystyrene, polycarbonate
