EXP 8 AND 9 Flashcards
is defined as the state in which any residue of the unit except for the fragments of the insoluble coating or capsule shell remaining on the screen of the test apparatus is a soft mass having no palpably firm core
Disintegration
are substances or agents added to compressed tablets to cause them to break apart or disintegrate when placed in aqueous medium
Disintegrants
Experiment 8 objective
To determine the rate of disintegration of uncoated tablets
Reagents/chemicals needed for Exp. 8:
6 ascorbic acid tablets
Equipment/Materials used for Exp. 8:
Disintegration apparatus
Procedures for Exp.8
- Place one tablet in each of the six test tubes of the basket and operate the
disintegration apparatus, using distilled water maintained at 37ºC as the
immersion fluid. - Set the disintegration apparatus timer every five (5) minutes for 6 times or until
the tablets begin to break. - At the end, lift the basket from the fluid. Observe.
USP Requirement: Ascorbic acid tablets should disintegrate within 30 minutes.
USP Requirement for Exp. 8
Ascorbic acid tablets should disintegrate within 30 minutes.
The first step for Exp. 8
Place one tablet in each of the six test tubes of the basket and operate the
disintegration apparatus, using distilled water maintained at 37ºC as the
immersion fluid.
The 2nd step for Exp. 8
Set the disintegration apparatus timer every five (5) minutes for 6 times or until
the tablets begin to break.
The 3rd step for Exp. 8
At the end, lift the basket from the fluid. Observe.
What type of water is used in Exp. 8 and the temperature maintained
Distilled water at 37 degrees Celsius
Every how many minutes was the Disintegration apparatus set to be checked and for how many times?
5 minutes; 6 times or until the tablets begin to break.
When phases exist together, the boundary between the two of them is termed an____
interface
The properties of the molecules forming the interface are often sufficiently different from those in the bulk of each phase that they are referred to as forming an
_____
interfacial phase
If a _____ and its _____ exist together in the same container, the liquid
takes the bottom part of the container.
liquid; vapor
The remainder of the container is filled up by the______, which, as with any gas, has the tendency to take up all available space.
liquid-vapor
Molecules in both the liquid and the Gas are in ______ and can move from the liquid into the vapor and back, from the vapor to the liquid.
constant motion
However, the distinct boundary
between the vapor and the liquid is preserved under ______ and the
______ does not destroy the equilibrium between these two phases due to
the ____ character of this boundary.
constant temperature; exchange of molecules; labile
Objectives of Exp. 9
- To determine and apply the different methods of measuring the surface tension of
liquids. - To observe and explain the different interfacial properties of surfactant.
Reagents/Chemicals used for Exp. 9
Liquid detergent
Water
Sulfur powder
Alcohol
Talc
Mineral oil
Tween 80
Equipments/ Materials used for Exp. 9
Equal-arm analytical balance
Ruler
Pipette
Aspirator
Glass capillary tube
Beaker
Dropper
Procedure for Capillary method
- Measure the diameter of the capillary tube.
- Fill the beaker with water and dip the capillary tube just below the surface of the
liquid. - Note the rise of liquid in the capillary tube. Measure the height of rise from the
surface of the liquid to the lower meniscus. - Record the data and compute the surface tension using the equation:
Surface tension (γ) = ½ rhρg - Repeat the same procedure with alcohol and mineral oil.
Formula for surface tension
(γ) = ½ rhρg
Surface tension (γ) = ½ rhρg
Where r =
radius of the capillary tube
Surface tension (γ) = ½ rhρg
Where h=
height of rise of liquid
Surface tension (γ) = ½ rhρg
Where p=
density of the liquid
Surface tension (γ) = ½ rhρg
Where g=
acceleration of gravity (981 cm/sec2)
INTERFACIAL PROPERTIES OF SURFACTANT
Procedure A
- Prepare four (4) concentrations of detergent solution as follows: 0.25%, 0.5%,
0.74% and 1.0%. - Make 2 marks on the pipette, approximately 1 mL in volume. Fill the pipette
with water up to the upper mark. - Allow the liquid to drain slowly up to the lower mark counting the drops.
- Record the number of drops and repeat one more time.
- Repeat the same procedure with detergent solutions prepared previously
Note: The greater the number of drops, the lower the surface tension.
INTERFACIAL PROPERTIES OF SURFACTANT
Procedure B
- Prepare 2 beakers filled with water. Sprinkle sulfur powder into it. Observe.
- In beaker 1, add 1 to 2 drops of detergent solution, and in beaker 2, add 1 to 2
drops of Tween 80. Observe. - Repeat the same procedure using talc powder instead of sulfur.
