Brainscape's Knowledge GenomeTM

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


See full index

Winter P1 > Pharm 734 Midterm > Flashcards

Pharm 734 Midterm Flashcards

1
Q

What are the main things to consider in Oral Drug Delivery?

A
  1. Advantages & Disadvantages of oral delivery route.
  2. Types of dosage forms used.
  3. Formulation factors affecting oral bioavailability
  4. Structure & Physiology of GI tract.
  5. Physiological factors affecting oral bioavailability
  6. Patient counseling
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are some advantages for oral delivery route?

A
  1. Patient acceptability & compliance.
  2. Large surface area for absorption.
  3. Rich Blood supply.
  4. Prolonged Retention.
  5. Possible for zero-order controlled release.
  6. Inexpensive.
  7. For local or systemic delivery.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are some disadvantages of oral drug delivery?

A
  1. Variability in patient population.
  2. Adverse reactions.
  3. Proteins & Peptides cannot be delivered.
  4. Metabolism & efflux issues.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What factors effect systemic absorption & Bio-availability?

A
  1. Physiochemical properties of the drug.
  2. Formulation Factors.
  3. Anatomy and physiology of the drug absorption sites.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are some physiochemical properties of drugs?

A
  1. pKa leading to Ionization
  2. log P between 1-3, Lipophilicity
  3. Solubility of drug in solution and absorption
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are some common types of dosage forms used for oral delivery?

A
  1. Solutions
  2. Emulsions
  3. Suspensions
  4. Powders
  5. Tablets
  6. Capsules
  7. Modified release granules, tablets & capsules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which formulation factors affect oral bio-availbility?

A
  1. Particle size
  2. Excipients
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the five most common types of Excipients?

A
  1. Wetting Agents/Surfactants
  2. Diluents
  3. Binders (adhesives)
  4. Disintegrants
  5. Lubricants
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are some advantages of Wetting Agents/Surfactants?

A

Help with dissolution by lowering interfacial tension (e.g. polysorbate 80)

Help with absorption of drug (e.g. sodium dodecyl sulfate)

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

What are some advantages of Diluents?

A
  • Bulk up formulations.
  • Lactose, Dextrose, Sucrose, Microcrystalling cellulose.
  • hydrophylic diluents promote rapid tablet disintegration (create channels in erosion matrix ER products).
  • hydrophobic diluents decrease dissolution rate of drug.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are some advantages of Binders (adhesives)?

A
  1. Bind powders during the granulation processes & help with compression.
  2. Starch mucilage, gelatin and polyvinylpyrrolidone (PVP)
  3. Coat drug particles so binders dissolution can determine drug release rate.
    - soluble binders (gelatin, pvp) -> fast drug dissolution
    - slow dissolving binders (starch) -> slow tablet disintegration & delayed drug release.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are some advantages of disintegrants?

A
  1. Swell in presence of water to burst open tablet. (slightly swell and press together)
  2. Starch and cation exchange resins.
  3. High swelling disintegrants -> rapid dissolution & higher bio-availibility.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are some advantages of lubricants?

A
  1. To help tablet ejection from machines & improve flow.
  2. Stearic acid & its Mg & Ca salts widely used.
  3. Tend to be hydrophobic & retard dissolution.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Transport Routes and Mechanisms

A

Transcellular passive diffusion

Paracellular passive diffusion

Carrier-mediated transport

Transport through transcytosis

Efflux Transporters

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

Gastrointestinal Motility

A

Phases I-IV (fasted state) 3-6hrs

Goes into the (Fed State) Liquids do not trigger fed state.

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

Migrating Myoelectric complex (MMC)

A

Housekeeper wave of phase 3, cleans out stomach and small intesting between meals, flushes undigested particles & un-disintegrated dosage forms

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

How is dosing affected by the MMC, how does stomach act prior to fed state?

A

Stomach remains in MMC until it senses food

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

What Factors influence gastric emptying

A

Volume Type of meal (high fat or high carbs decrease rate of emptying)

Physical state of gastric contents (liquids vs solids)

Hydrogen ion concentration (acidity)

Viscosity (faster for less viscous)

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

Metabolism in the GI tract occurs in _______, ________ or ______ and experiences ________

A

Gut fluids, within microvilli of enterocytes in cytoplasm or lysosomes, or SI mucosa

The first pass Effect

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

Cytochrome P450-3A4

A

Is highly expressed in SI

Metabolizes many drugs (120+)

Inhibitis pre-systemic clearance of grapefruit juice, which can increase BA of some drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Effect of grapefruit juice on BA

A

Inhibits Cyp3A4

may need to stop drug use or lower dose due to increased time

generally raises BA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

P-glycoprotein (P-gp) drug Efflux is often expressed in…

A

Energy Dependent Drug efflux pump,

There is high expression in epithelial cells of SI Hydrophobic vacuum cleaner (lipophilic, Cationic)

Can effect Oral BA significantly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Counseling with Grapefruit Juice

A

If you consume GF juice, let the physican and pharmacist know you are starting a new medication

Avoid GF with some drugs

Many mixed juices contain GF

Alternative medicines if not willing to give up GF juice.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Name a method to decrease drug BA

A

increased activity of P-gp will result in a decreased BA of the drug

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How does presence of Food effect drug absorption?

A

In general, drug absorption is less efficient when food is present in the GI tract.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

In which dosage forms does GI transit not change significantly?

A

Solutions Suspensions/Dispersions IR dosage forms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

In which dosage forms does GI transit change significantly?

A

EC tablets

ER tablets (matrix or reservoir systems)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Drug Delivery Systems consist of what two major components?

A

Drug/Active compound with intrinsic pharmacological activity (drug/Excipient)

Delivery System that insures the active compound is transported from the site of administration to site of action. (Administration device and route of administration)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Ideal characteristics of a drug delivery system?

A

Release the drug at the appropriate location

Its Convenient and easy for patient to take

Its aesthetically pleasing to the patient (taste, smell, appearance)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the purpose of drug excipients?

A

Drug Release

Stability

Elegance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What are the components of drug solutions, what excipients are used and what are the routes of administration?

A

Active drug completely dissolved in a medium (aq or non-aq)

Excipients - Buffers, preservatives, Stabilizing agents (antimicrobial or antioxidants), Flavors, colors

Routes of administration - Oral, Parenteral, topical, nasal, pulmonary, otic and opthalmic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are the components of drug dispersions, what excipients are used and what are the routes of admnistration?

A

drug in two immiscible phases

(suspension (s/aq) or emulsion (aq/aq))

Excipients - suspending or emulsifying agent, buffers, preservatives, stabilizing agents, flavors, colors

Routes - Oral, Parenteral, topical, otic, opthalmic, nasal and pulmonary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What are the components of Semisolids, what excipients are used and what routes of administration?

A

Drug in Creams, gels, ointments or pastes

Excipients - Emulsifiers, Viscosity-increasing agents, antimicrobial agents, antioxidants, stabilizing agents

Routes - Topical, transdermal, opthalmic, vaginal and rectal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What are the dosage forms of solids, what routes of administration?

A

Tablets, Powders, Capsules Majority Oral, topical, vaginal and pulmonary.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What are the benefits of Local Action drugs?

A

They work as intended at their sites of action, and proximity to application site

Side effects are caused primarily by absorption into blood.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What are the uses of systemic effect drugs?

A

Their intended site of action can be in close proximity or distal to the application site.

Lack of efficacy caused by inappropriate blood levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Oral drug Delivery adminstration and absorption location

A

drug administered through the mouth and intended for absorption via the GI tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Oral Trans-mucosal

A

drug administered into the oral cavity (local or systemic (buccal tabs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Transdermal drug delivery

A

Drug administerd on the skin for systemic absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Topical drug delivery

A

Drug for the treatment of the local conditions of the skin (do not want absorption through the skin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Opthalmic drug delivery

A

administerd ocularly for the treatment of local conditions of eyes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Nasal Drug delivery

A

administered into nasal cavity for topical or systemic use

43
Q

Vaginal Drug delivery

A

Topical application for local or systemic treatment

44
Q

Anal/Rectal drug delivery

A

for the local treatment or systemic absorption

45
Q

Parenteral drug delivery

A

administration by injection, includes intramuscular, intravenous or subcutaneous

46
Q

Types of Capsules

A

Hard gelatin Capsules (HGC) Soft Gelatin Capsules (SGC)

47
Q

Advantages Of Capsules

A

Versatile Can conceal odor and mask taste Easy to fill/administer For placebos can be used to administer liquids or solids Have higher oral BA than tablets Drugs may have higher stability Convenient

48
Q

Disadvantages of Capsules

A

Tend to be larger than tablets, (swallowing issues)

Tampering issues

Requires specialized manufacturing equipment

Liquid filled capsules can have stability problems

49
Q

Alternatives to Gelatin Capsules

A

Pullulan

Hydroxy Propyl Methyl Cellulose

50
Q

Physiochemical drug properties needed for Capsules

A

Liquids (non aq) or Solids

All types of drugs and excipients (except highly hygroscopic)

Most used for drugs with poor compression properties that require a high dose

51
Q

Presence of what chemical components distinguishes soft shell capsules form hard shell capsules

A

Glycerin or Sorbitol which act as a plasticizer

52
Q

Possible Capsules contents include:

A

Liquids (volatile oils, aromatic or aliphatic hydrocarbons, ethers, esters, alcohols)

Combination of miscible liquids

Solutions of solid in liquid (Suspensions)

Solids

53
Q

Capsule routes of administration

A

Oral and Vaginal

54
Q

Tablets in Capsules

A

Capletception is a thing in both commercial and clinical trials (used to disguise in placebo/ blinded studies)

55
Q

In a compound setting, what type of capsules can be used, what methods are used?

A

Hard Gelatin Capsule

Punching

Filling Machines

56
Q

Between Capsule and Tablet, which dosage forms allows for higher bioavailability, and what is the rate limiting step?

A

Capsule allow for more BA

Rate limiting step is rupture, dissolution of gelatin in G

57
Q

What Stability issues arise with capsules?

A

Physical (moisture content changes in shell)

Chemical (Depends on drug exposure, or use of opacifiers, antioxidants to protect drug)

Microbiological (contain preservatives to prevent microbial growth)

58
Q

What is the moisture content of HGCs vs SGCs

A

HGC - 13-16%

SGC - 20+%

59
Q

Routes of administration for SGC

A

Oral, Vaginal, Rectal or Opthalmic

60
Q

Advantages of SGC

A

liquids can be encapsulated Specialized dosage forms can be prepared (chewable, ER, etc)

61
Q

Disadvantages of SGC

A

Water containing materials cannot be used

Highly moisture sensitive

Stick to each other

More costly than HGC

Increased possibility of interactions between drug and shell

62
Q

What percentage of patients report difficulty swallowing tablets? Report they hesistate taking medication due to tablet size?

A

40%, 84%

63
Q

SGC stability issues

A

Physical (capsules stick, moisture content (cracking/dissolution) \

Chemical (depends on drug)

Biological (microbial growth bigger issue than HGC)

64
Q

How are Tablets define and classified?

A

Tablets are solid dosage forms containing drug substances and excipients prepared by molding or compression (IR, Rapidly Dissolving, modified Release)

65
Q

What is Fick’s Laws of diffusion?

A

Process by which molecules spread from high areas of [C] to low.

J = -D (dc/dx)

J - flux of component across plane

D - diffusion coeffecient,

dc/dx - concentration gradient

66
Q

What is the Stokes-Einstein Equation

A

D = (kT) / (6 π η r)

Helps define diffusion of solvents

67
Q

What is Dissolution and what is a dissolution rate?

A

The act of a solute going into a solution

Dissolution Rate is the time required for a drug substance to dissolve in the fluids at the absorption site. ( often the rate limiting step in the absorption process)

68
Q

What is the Noyes-Whitney equation?

A

Another equation which helps determine the dissolution and diffusion of a drug

dC/dT = DS/Vh (Cs-C)

69
Q

What are some ways to increase dissolution rates?

A

Decrease particle size Increase solubility in diffusion layer

Alter pH of dissolution medium

Increase agitation of dissolution medium

70
Q

What is Disintegration?

A

The process of by which a tablet breaks down into coarse and finer particles.

71
Q

What is Deaggregation

A

The process by which coarse particles break up into finer particles

Can be increased by using deaggregants and increasing agitation

72
Q

What excipients are the most common

A

Diluents

Binders/adhesives

Disintegrants

Lubricants

Glidants

Preservatives

Coating polymers

Antioxidants/Stabilizers

Colorants & Flavorants

73
Q

Why are excipients needed?

A

Spatial control of drug release protect the drug in certain regions of body

Aid in drug absorption

Ensure product stability for shelf life of product

Aid in drug identification

Improve drug’s organoleptic properties for patient compliance

Aid in the manufacturing process

74
Q

Effect of excipients on drug absorption

A

Effecting tablet disintegration

Effecting drug dissolution

Effecting drug absorption-permeation enhancer and p-glycoprotein inhibitor

75
Q

What are the 11 types of tablets?

A

Compressed tablets

Multiple compressed tablets

Sugar coated tablets film coated tablets gelatin coated tablets

Enteric coated tablets

Buccal and sublingual tablets

Chewable tablets

Effervescent tablets

Instantly disintegrating/dissolving tablet

Vaginal tablets

76
Q

What are the most popular tablets?

A

Compressed tablets, made from one compression cycle

77
Q

What is the structure of multiple compressed tablets and what are the reasons for its use?

A

multi-layered tablet or tablet within tablet (at least 2 layers)

To separate incompatible drugs into different layers

To deliver drugs at different rates or different sites

78
Q

What are the benefits of sugar coated tablets?

A

Designed to dissolve quickly after swallowing, used to mask taste, smell and prevent oxidation

79
Q

What are film coated tablets and what are its advantages?

A

Compressed tablets w/ thin layer of polymer useful for IR or MR More durable and less time consuming than sugar tabs

80
Q

Non-aqueous film-coating components and purpose

A

Surfactants to enhance spreadbility of film during application.

Opaquants and colorants to make the appearance of the coated tablets handsome and distinctive

Sweeteners, flavors and aromas

Glossant to provide luster without polishing

Volatile solvent to allow spread of other components over tablet

81
Q

Chewable tablet properties

A

Compressed tablet that is chewed to dissolved smoothly and rapidly. It is useful for large tablet administration in children and for adults with trouble swallowing.

82
Q

Effervescent Tablet properties

A

Tablets that dissolve rapidly in water. (contains sodium bicarbonate or citric acid which breaks down into carbon dioxide in water)

83
Q

Instantly disintegrating and dissolving tablets properties

A

Rapidly dissolve in the mouth (10sec-1min) Liquiefy on tongue & patients swallow liquid

packing and storage is important to avoid moisture absorption

84
Q

Vaginal Tablets design

A

Ovoid shaped for insertion, requires an administration device Requires SLOW dissolution of tablet with no disintegration to release drug

85
Q

Tablet advantages

A

Convenient Can modulate drug release

Except for proteins, all drug classes can be administered by tablets

Inexpensive easy to manufacture highest stability of all dosage forms

86
Q

Tablet Disadvantages

A

Absorption greatly dependent on physiological conditions

Certain drugs have poor compressability, hard to make into tablets

Difficult to administer in some populations

87
Q

Modified Release Dosage forms include:

A

Delayed release (DR)

Repeat Action (RA)

Targeted Release

Extended Release (ER, XR)

88
Q

What are the pharmacokinetics of the different release tablets?

A
89
Q

What are some examples and advantages of Delayed Release dosage forms?

A

IR w/ delayed onset

Enteric Coated dosage forms

To protect the drug from stomach pH

To protect the stomach from iritation from drug

To prevent regurgitation

90
Q

What are the properties and coating materials used in EC tablets

A

Insoluble @ pH 1-3

Soluble @ pH 5-8

Coating Materials include: Cellulose Acetate phthalate, Polyvinylacetate phthalate, HPMC phthalate, Pharmaceutical Shellac, HPMC succinate

91
Q

What is the purpose of Repeat action dosing of an IR with an additional DR or ER?

A

Convenience of 2 doses in 1 unit, increases patient compliance, is accomplished using a time-dependent polymer coat

92
Q

How is targeted release achieved?

A

Drug release is targeted to a specific region by coating drug in a polymer that only dissolves in a certain pH setting. Especially helps with Colonic Drug delivery.

93
Q

Drug Candidates for ER products require….

A

A Moderate rate of the drug absorption and excretion (slow –> long acting)

Uniformly absorbed for the GI tract

Administered in relatively low dose

Wide Therapeutic window

Used for the treatment of chronic rather than acute conditions

94
Q

What are the goals of an ER tablet?

A

Constant Plasma Concentration (mimic IV infusion at SS)

Input rate into Plasma = elimination Rate from plasma

Tablet must not disintegrate (Dissolve slowly and consistently)

95
Q

ER Dosage Form system strategies include:

A

Coated Particle Systems

Microencapsulated Systems

Matrix Systems

Reservoir Systems

Osmotic Systems

Ion exchange Resins

96
Q

Coated particle System characteristics

A

Granules, Beads or pellets (coated w/ water soluble polymer)

Coat thickness varies (variable dissolution w/ 3-4 sets of granules in a dose, may have different colors to differentiate)

Mixture of coated granules ( filled into capsules, or compressed into tablets)

Advantages (Large surface area for consistent dissolution, spreads the dose out over entire GI tract)

97
Q

Microencapsulated System characteristics

A

Tiny Microcapsules or microspheres prepared by coating solids, liquids or gases

Coating w/ Insoluble, semipermeable membrane that allows the drug to diffuse out of the microcapsule or the microsphere

Different rates of drug release by changing ratio of core to wall

98
Q

Soluble Matrix System Characteristics

A

Drug + slowly dissolving Polymer = granule

Granules with (ER) and without polymer (IR)

Polymer - HPMC

No disintegrants used

Water penetrates the tablet, and a gel forms on surface and soluble drug diffuses through it.

Pevents disintegration and slow dissolution.

Drug Release controllled by Erosion Rate, Particle size, solubility and diffusion

99
Q

Insoluble Matrix system characteristics

A

Drug dispered in an insoluble matrix

Matrix shell remains intact and is excreted in feces

Contains excess drug to maintain constant in its dissolution rate

Its channel formation contrals release rate, and often uses a channeling agent such as NaCl for water soluble excipients

100
Q

Reservoir systems characteristics

A

Core of drug + excipients surrounded by a polymer coat/membrane

Membrane is insoluble at any pH, Permeable to water and dissolved drug

Rate of release is controlled by Nature and thickness of membrane

Empty shell is excreted in feces

Tablet cannot be split

101
Q

Osmosis based system characteristics

A

Core tablets surrounded by semi-permeable membrane coating with a tiny hole.

Water permeates the membrane, and using osmosis pushes drug out the shell into the body.

Rate of release is constant as long as osmotic gradient remains constant

Release rate depends on SA, thickness of membrane, and diameter of hole

102
Q

Ion Exchange Resin characteristics

A

Drug forms complex w/ resin through ionic interactions

THis complex is put into a tablet/capsule or suspended in liquid

Drug release is dependent upon pH of the environment or electrolyte concentrations in the environment

103
Q

What are the physiochemical drug properties needed for ER?

A

Dose size < 500 mg

MW < 500 Da

Solubility - Intermediate (highly soluble -> Rapid dissolution -> difficult to formulate) (Poor Solubility -> dissolution-limited -> difficult to formulate)

Log P between 1-3

Stable in GI tract: pH stable & stable to enzymes & microbes

Ionization - only uncharged molecules will permeate

104
Q

What are the Biological parameters for drugs in ER dosage forms?

A
  1. Rate of drug absorption >>>> rate of drug release from dosage form
  2. 2 < t1/2 < 8hr
  3. Not potent
  4. Wide therapeutic index (MTC >> ER strength)
  5. Used for chronic therapy
  6. Should not have high accumulate in tissues (large Vd)
  7. Should not exhibit saturable kinetics
  8. Should not induce/inhibit enzymes
  9. Not for antibiotics (resistance development)

Winter P1 (8 decks)

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