Brainscape's Knowledge GenomeTM

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


See full index

Pharmacy Practice Lab > Lab 2 > Flashcards

Lab 2 Flashcards

1
Q

Must all drugs be soluble in water? explain

A

ALL drugs must be soluble in water to some extent, regardless of dosage form.
This is so because it enables systemic absorption and therapeutic response.

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

The dosage form used for administering a drug is generally selected based on….

A

the drug’s solubility

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

What is done if a drug is extremely insoluble?

A

more soluble derivatives of the parent drug are prepared by salt formation and chemical complexation

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

A “true solution” is formed when….

A

the solute molecules completely dissolve in the solvent to give a clear, transparent, homogeneous liquid

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

In a true solution, can the solute and solvent be separated by filtration? Is the solution able to transmit light?

A

A true solution CANNOT be separated by filtration. A true solution IS able to transmit light

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

What is a colloidal solution?

A

a colloidal solution is a visibly clear, transparent homogenous liquid. However, a colloidal solution reflects light (Tyndall effect)

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

What is a saturated solution?

A

a saturated solution is a solution which contains the MAXIMUM amount of dissolved solute (ie: at its maximum solubility)

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

What is a supersaturated solution?

A

a supersaturated solution forms when the quantity of solute is greater than its solubility

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

Both saturated and supersaturated solutions tend to be…..

A

UNSTABLE and very likely to crystallize or precipitate with changes in temperature, addition of other ingredients, and loss of solvent (evaporation)

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

Addition of other substances in saturated and supersaturated solutions can result in precipitation and crystallization. What is the term for these added substances?

A

excipients

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

Differentiate between precipitation and crystallization

A

Precipitation is the formation of very small particles of the solute
Crystallization occurs when these particles have a well-defined, crystalline structure

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

Most substances are (endothermic or exothermic) when dissolving

A

endothermic (absorb heat)

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

If a substance is endothermic when dissolving, will the temperature of the solution increase or decrease?

A

decrease since the substance is absorbing heat from the solution

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

In the case of an endothermic solute, will its solubility increase or decrease with increasing heat?

A

solubility will increase

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

Pressure affects the solubility of _____ but generally does not affect the solubility of ___

A

Pressure affects the solubility of GASES but generally does not affect the solubility of SOLIDS AND LIQUIDS

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

Solubility _______ with increasing molecular size

A

decreases

17
Q

Water is the solvent. Will a molecule with hydrophobic groups be soluble?

A

no

18
Q

Water is the solvent. If the solute has polar groups (acids, esters), will it be soluble?

A

yes

19
Q

Solutes exist as ____ and ___ forms

A

amorphous and crystalline

20
Q

Solutes exist as amorphous and crystalline forms. Which is more soluble and why?

A

the amorphous form is more soluble. this is so because crystalline polymorphs have well-fitted molecular arrangements that are less likely to interact with the solvent

21
Q

Polymorphic changes can occur during….

A

precipitation

22
Q

Dielectric constant is a measure of…

A

the solvent’s ability to separate opposing molecular charges

23
Q

The higher the dielectric constant, the _____ the polarity of the solvent and the _____ likely it is to interact with nonpolar solutes

A

the higher the dielectric constant, the GREATER the polarity of the solvent and the LESS likely it is to interact with nonpolar solutes

24
Q

Explain the pros and cons of using organic compounds as solvents

A

pro – they have low dielectric constants and are thus able to dissolve non polar solutes

con — they are toxic in high concentrations

25
Q

What is the purpose of the cosolvent system?

A

The cosolvent system consists of several solvents to create an aqueous mixture with a desirable dielectric constant, but without the toxic effects of organic compounds. This system decreases the difference between the polarity of the solute and solvent

26
Q

The apparent dielectric constant of a mixture of solvents (cosolvent system) can be calculated which 2 ways?

A

the algebraic and allegation methods

27
Q

What is another word for “particle size reduction”

A

pulverization

28
Q

What is the purpose of pulverization

A

pulverization increases the surface area of the drug that comes in contact with the solvent and thus increases the dissolution rate

29
Q

Does reducing particle size increase the intrinsic solubility of a substance?

A

NO

30
Q

Explain the pros and cons of agitation

A

pro — stirring (agitation) increases the rate of dissolution

con — excessive agitation can increase entrapment of air and foaming which could result in degradation of a drug that is easily oxidized, as well as errors in volume/concentration of the product

31
Q

Hydrophobic powders do not mix well with water due to _____. What can be done to help the solubilization process in this case?

A

surface tension. Wetting agents can increase the contact of hydrophobic drugs with water and aid in the solubilization process

32
Q

Pharmaceutical solutions are….

A

solids dissolved in a liquid vehicle (usually water of a combination of solvents and ingredients to dissolve the solids)

33
Q

Gives some pros and cons of pharmaceutical solutions vs solid dosage forms

A

pro— solutions provide a faster onset of activity, is homogenous, and provides uniform flexible dosing. Also has several routes of administration (oral,IV) and is useful for patients who have difficulty swallowing pills

con— more likely to have stability and appeal (taste) issues. more likely to leak

34
Q

What is intrinsic solubility?

A

the solubility of the drug in a solvent when the drug is in an uncharged state

35
Q

Name the 5 USP descriptive terms for solubility

A

parts of solvent (mL) needed to dissolve 1 part (g) of solute

Very soluble = less than 1mL
Freely soluble = 1-10mL
Soluble = 10-30mL
Sparingly Soluble = 30-100mL
Slightly soluble = 100-1000mL

36
Q

What are 3 techniques used to improve the solubility of drugs in aqueous solutions?

A
  1. cosolvent
  2. adjusting pH
    3.using solubilizers and complexing agents
37
Q

cosolvents are usually…….

A

alcohols or other organic solvents . Added to the primary solvent in small amounts to increase the solubility of a poorly soluble compound

38
Q

Selecting of the co-solvent is based on…

A

the dielectric constant of the drug.
For good solubility, the difference of the dielectric constant between the drug and the solvent mixture should be small

39
Q
A

Pharmacy Practice Lab (10 decks)

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