Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharm303 LABS > Lab 2: solutions - formulation and evaluation > Flashcards

Lab 2: solutions - formulation and evaluation Flashcards

1
Q

What are the advantages of solutions?

A

content uniformity
thermodynamically table
drug immediately available for absorption
easy to swallow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the disadvantages of solutions?

A 
inconvenient to store and transport
low stability
requires preservative
requires accurate measurement
hard to mask bad taste of drugs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the 3 main types of solutions investigated in this lab?

A

aromatic waters
simple syrup
amaranth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are aromatic waters?

A

A class of aqueous solutions containig saturated solutions of volatile oils or other aromatic substaces.

They are used in the pharmacy for their medicinal value as well as their flavouring agent

we used anise and peppermint

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is simple syrup?

A

a concentrated solution of sucrose in water. It is used as a sweetener

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is amaranth?

A

A commonly used colouring agent of pharmaceutical preparations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the aim of lab 2?

A

to prepare and evaluate the quality of

aromatic waters anise and peppermint
simple syrup
amaranth solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the function of purified talc?

A

It is an adsorbent and is added to remove excess oil.

I.e a distributing agent which speeds up the mixing process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is weight per volume of concentrated water?

A

density

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the components of a polarimeter?

A

Polariser
Sample tube
Analyser/Analysing filter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does the polariser do?

A

Filters out lightwaves so that only polarised light passes through the sample

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does the sample tube do?

A

Contains the optically active solution causing the plane of polarised light to rotate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does the analyser do?

A

This filter is rotated until no light passes through

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does the viewer see in a polarimeter?

A

The viewer rotates the analysing filter to find optical zero. This is when both the circle and the line are white. The degree at which this occurs is noted.

The viewer then slowly rotates the analyser until the circle is white and the horizontal column is black. The degree at which this occurs is also noted

The optical rotation of the sample is the difference between the two degrees.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the optical rotation?

A

The angle through which the plane of polarisation rotates when a polarised light is passed through a substance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which sort of molecules do optical rotation occur in?

A

Chiral molecules

Solids with rotated crystal plates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does a + value of optical rotation indicate?

A

the plane of polarised light is rotated clockwise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does a - value of optical rotation indicate?

A

the plane of polarised light is rotated anticlockwise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What does the optical rotation of a sample depend on?

A

The number of optically active species through which the light passes.

i.e. depends on both the sample path length and the analyte concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the formula for the specific optical rotation measured at 589.3nm at 20 degrees?

A

1000a/lc
where

a is the degree of rotation (degrees)

l is the length of the polarimeter tube (dm)

c is the concentration of the sample (g/L)

D is the wavelength of the sodium D- line (589.3nm)

21
Q

What does 1 dm equal?

A

10cm

22
Q

What is specific gravity?

A

The ratio of density of the test substance to the density of a reference substance.

This measures the RELATIVE density

23
Q

What are the reference substances to measure relative density for liquids and gases?

A 
liquids = water
gases = air
24
Q

Why is the relative density of a syrup not measured with a pycnometer?

A

The syrup is too thick so its relative density must be measured using a hydrometer to a reference substance, water.

25
Q

For the formulation of Amaranth solution (APF) why must the solution be immediately stirred after adding the compound hydroxybenzoate solution?

A

methyl and propyl paraben in propylene glycol is insoluble in water. hence the solution must be immediately stirred to avid precipitation.

26
Q

What is weight per mL? (g)

A

the weight in grams of 1mL of liquid

27
Q

What is density? (Kgm^-3, g/mL Kg/L)

A

the ratio of mass to volume AT A SPECIFIC TEMPERATURE

28
Q

What is the relative density?

A

the ratio of the density of a substance to the density of a reference material (air or water)

29
Q

What is apparent density?

A

the weight in air per unit volume

30
Q

What is talc?

A

a purified, hydrated, magnesium silicate.

31
Q

How does talc adsorb the excess oil?

A

It has a high surface area and aDsorbs excess oil.
This can then be filtered as filter pores are much smaller than the talc particles.
This leaves the solution free of the undissolved or excess oil.

32
Q

What is invert syrup?

A

mixture of glucose and fructose prepared by hydrolysing a 66.7%w/w solution of sucrose with a suitable mineral acid

This is neutralised with calcium carbonate or sodium carbonate.

The degree of inversion is at least 95%

33
Q

What is an example of a suitable mineral acid used in the formulation of invert syrup?

A

hydrochloric acid

34
Q

How is a disaccharide formed?

A

when 2 monosaccharides undergo a condensation reaction resulting in the elimination of small molecule such as water.

35
Q

What kind of a sugar molecule is sucrose?

A

a disaccharide comprising of glucose and fructose

36
Q

Is sucrose optically active?

A

yes

37
Q

What is a Hydrometer?

A

cylindrical glass with a bulb weighted with mercury or lead to make it float.

This is used to measure the relative density of syrup

38
Q

What is Archimede’s principle?

A

that an object suspended in fluid causes the fluid to be displaced by the submerged part of the suspended object.

There is an upward force on the object that equals the weight of the displaced fluid

This causesthe object to float.

39
Q

What does Archimede’s principle tell us about the density of a substance?

A

That the lower the density of the substance, the farther the hydrometer will sink

40
Q

What is amaranth?

A

a short lived plant which blossoms densely packed flowers in the summer or autumn.

41
Q

What are amaranth flowers a source of?

A

a deep red dye

42
Q

What is synthetic amaranth?

A

The synthetic dye made similar to that of the amaranth flower dye

43
Q

What chemical structure group does amaranth belong to?

A

polycyclic aromatic hydrocarbons

44
Q

What is CHB?

A

compound hydroxybenzoate solution
This is a preservative effective over a wide pH range.
Its maximum chemical stability is at pH 4-5

45
Q

What are parabens?

A

organic esters (e.g. methyl hydrozybenzoate, propyl hydroxybenzoate)

These are subject to degradation to form para acid and their corresponding alcohols

46
Q

What conditions cause the degradation of parabens to para acids + their corresp. alcohols?

A

the combination of temperature, pH and time

47
Q

What is the effect of pH and ionisation on the methyl and propyl hyroxy benzoate parabens?

A

MHB and PHB have a pKa of 8.5
In pH 4-5 they will be 99.9% unionised and are therefore able to passively diffuse into microbial cells to exert their effect.
They are also the most stable at pH 4-5

48
Q

What is the effect of pH on the stability of lemon syrup?

A

A low pH such as 1.2, will cause hydrolysis of the lemon syrup. This will cause glycosidic bond to break resulting in glucose + fructose monosaccharides

Given that the optical activity is now -19° (not the range +56 to 60° expected for sucrose,) this also tells us that we do not have sucrose anymore.

NB: Glucose and fructose have optical activities of +52.3 to +53.3° and -91 to -93.5°, respectively.

Therefore, the -20° is the optical activity expected for the mixture of glucose and fructose. Note the mean of the two sugars is (+52º + (-92.25º)) / 2 = -20°

49
Q

In the evaluation of aromatic waters such as concentrated anise water, why did the density of anise water not comply with the BP requirements?

A

We did not leave the talc to interact with the solution long enough so it did not absorb the excess oil.
This meant that filtering of the talc removed a lot of the oil resulting in a lower density than the BP requirements

Pharm303 LABS (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions