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Dosage Forms > Exam 3 Second Set of Lecture Slides > Flashcards

Exam 3 Second Set of Lecture Slides Flashcards

1
Q

What are the physiological factors that affect absorption?

A
  1. absorbing surface area
  2. residence time at absorption site
  3. pH changes in lumen
  4. permeability/perfusion → functional and molecular characteristics of transporters and metabolism
  5. dietary fluctuations/effects
  6. complexation/protein binding
  7. biliary uptake and clearance
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2
Q

What is the importance and purpose of epithelia?

A

They are used for external surfaces (epithelial cells are epitheliod) → sits on a layer of extracellular matrix proteins such as collagen and fibronectin which is called the basal lamina → epithelial cells are polarized with directional transport (have transporters on the outer membrane)

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3
Q

What are the different types of epithelia?

A
  1. simple squamous
  2. simple columnar
  3. translational
  4. stratified squamous
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4
Q

What is simple squamous epithelium?

A

A thin layer of flattened cells that are relatively permeable → lines most blood vessels, placenta, endothelial cells (ex. is air sacs in the lungs)

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5
Q

What is simple columnar epithelium?

A

usually found in the GI tract (ex. intestine)

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6
Q

What is translational epithelium?

A

comprised of several layers with different shapes → usually required to stretch

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7
Q

What is stratified squamous epithelium?

A

multiple layers of squamous cells that cover areas subject to wear and tear → skin is an example of a barrier that comes from keratinization (ex. esophagus)

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8
Q

Where are endothelial cells found?

A

Lines the inside surfaces of body cavities, blood vessels, and lymph → have simple squamous morphology

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9
Q

Where can you find pseudostratified ciliated columnar epithelium?

A

the respiratory tract

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10
Q

Where can you find simple cuboidal epithelium?

A

the kidneys

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11
Q

What are tight junctions?

A
  • like a Ziploc seal around the cells and is important for the function of the confluent epithelium and endothelium
  • restrict solute movement between the cells (paracellular)
  • polarize cells into apical (luminal/blood facing) and basolateral (abluminal/brain facing) areas
  • allows for differing functions between the two membranes
  • can involve up to 50 proteins
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12
Q

What does sialic acid do?

A

Makes the glycocalyx more anionic

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13
Q

What defines a cell as a living unit?

A

Being enclosed by one or more membranes

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14
Q

What is the biological membrane and what is its purpose?

A

A semi-permeable membrane that permits the rapid passage of some chemicals while preventing the passage of others which isolates cellular contents from the environment (forms a barrier) → lipid composition is polarized and the intracellular membrane lipids are different than the extracellular lipids

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15
Q

What can go through tight junctions?

A

Tight junctions are anionic in charge so cationic drugs can go through faster and anionic drugs go through slower

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16
Q

How can depolarization of phospholipids lead to cancer therapy?

A

Phosphatidylserine is normally found in the inner leaflet of the bilayer with other cationic lipids → when cells die, get mutated or infected, the lipid polarization changes which can interfere with drug transport

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17
Q

Does cholesterol only have harmful effects on membranes?

A

No → provides fluidity at lower levels (which is good) but when it exceeds a certain level in the membrane, the membrane undergoes a phase transition and forms a liquid crystalline state called atherosclerosis in the vasculature

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18
Q

What is the permeability coefficient?

A

Put into well and grow the cells in which the drug was placed on top of the cells and grow out the cells for 21 days and measured how much drug got to the bottom → called the permeability coefficient (if multiplied by the initial concentration we put in, that would be flux)

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19
Q

Does permeability have units?

A

It’s a rate → the faster drug crosses the intestinal barrier, the more likely it is to be absorbed (the faster the higher the rate, the better)

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20
Q

What is the importance of PAMPA?

A

could see the permeability and the lipophilicity

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21
Q

What is the significance of lipid composition varying according to the organ?

A

Changes in the fatty acid/lipid composition can dramatically influence the passive absorption and function of cells

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22
Q

What are examples of passive (non-saturable) intestinal transport mechanisms?

A
  1. paracellular (between cells)

2. transcellular (through cells)

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23
Q

What are examples of carrier-mediated (saturable) intestinal transport mechanisms?

A
  1. active (energy dependent)

2. facilitated diffusion (energy independent)

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24
Q

Passive drug transport follows what?

A

Fick’s first law: donor well → membrane → acceptor well

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25
Q

What affects paracellular transport?

A

hydrophilicity, molecular size and shape, pKa of ionizable groups

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26
Q

What affects transcellular transport?

A

lipophilicity (H binding potential, hydrophobicity), molecular size and shape, pKa of the ionizable groups

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27
Q

What do the typical permeability assays tell you?

A

PAMPA: passive diffusion
PAMPA+Caco-2: mechanistic information
Caco-2: passive, active influx, efflux, and paracellular

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28
Q

What does the typical graph look like for Caco-2 permeability (y axis) vs PAMPA permeability (x axis)

A

A straight linear line (most transport is passive diffusion) → if it deviates up/positively, it indicates absorptive influx (active uptake) and/or paracellular transport → if it deviates down/negatively, it indicates secretory efflux transport/metabolism or even MDR1/pgp

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29
Q

What are drug transporters?

A

Membrane bound proteins that are widely distributed throughout the body and is prominently on apical and basolateral surfaces or organs involved in clearance

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30
Q

What is the physiological role of drug transporters?

A

Move important molecules across membranes that wouldn’t normally go across → includes moving drug molecules across membranes

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31
Q

Drug transporters are a crucial determinant of what?

A

Tissue and cellular distribution of drugs for drug clearance and also sanctuary organs

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32
Q

Variations in drug transporter activity are major determinants of what?

A

Drug response and drug safety

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33
Q

What are the the 2 nutrient and xenobiotic transporters?

A
  1. solute carrier (SLC)

2. ATP binding cassette (ABC)

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34
Q

What are solute carriers?

A

has 43 subfamilies, more than 300 members identified, generally influx or secretory efflux transporters, examples include PepT1, OATs, OATPs

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35
Q

What are ATP binding cassettes?

A

catalyze ATP to ADP, has 7 subfamilies, 50 identified members, generally efflux-multidrug resistant transporters, examples include pgp, MRPs

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36
Q

What is the nomenclature of transporters?

A

transporter type → family number → species variant

example: human PepT1 is SLC15A1

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37
Q

What is concerted metabolism?

A

phase I and phase II metabolism which is also known as conjugation

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38
Q

What are the 6 routes of permeability?

A
  1. influx transporter mediated
  2. passive transcellular
  3. passive transcellular and efflux
  4. passive paracellular
  5. metabolism
  6. efflux of the metabolites
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39
Q

What do influx transporters do?

A

Transfers substrates into cells

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40
Q

What do efflux transporters do?

A

Pumps substrates out of cells

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41
Q

What do absorptive transporters do?

A

Transfers substrates into the systemic blood circulation → 2 transporters on both sides of the membrane to pump the drug in (example is endothelial and placental)

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42
Q

What do secretory transporters do?

A

Transfers their substrates from the blood circulation into bile, urine, and/or GI lumen

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43
Q

What affects passive paracellular permeation?

A
  1. hydrophilicity
  2. molecular size and shape
  3. pKa of the ionizable groups
  4. linear increase in permeability with increasing concentration
  5. adjuvants can open tight junctions and increase transport
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44
Q

What affects passive transcellular permeation?

A
  1. lipophilicity
  2. molecular size and shape
  3. pKa of ionizable groups
  4. linear increase in permeability with increasing concentration
  5. dissolution/solubility limited with high lipophilicity
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45
Q

What affects facilitative/active transcellular permeation?

A
  1. affinity (Km) and capacity (Vmax/Jmax)
  2. concentration dependent saturation
  3. expression level (constitutive, induced)
  4. function (drug-drug interactions, inhibition)
  5. excipients like surfactants that can limit the effects of efflux like pgp or BCRP
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46
Q

What is the equation of Pbarrier?

A

Pbarrier = Ppara + Ppassive,trans + Pactive,trans ± Pactive,trans

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47
Q

What can affect the net absorption of drug?

A

efflux and metabolism

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48
Q

What is the difference between affinity and capacity?

A

Affinity is how tight the drug binds to the transporter while capacity is the rate driving the transport in

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49
Q

What is the importance of COX-2?

A

COX-2 is involved in inflammation and COX-2 inhibitors are needed for headaches and the inflammatory response

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50
Q

Where does all drug absorption occur?

A

ascending colon (colon is great for water absorption)

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51
Q

What type of epithelium is in the oral cavity (buccal) and sublingual?

A 
oral cavity (buccal) → stratified squamous
sublingual → simple squamous
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52
Q

What type of epithelium is located in the esophagus and the trachea?

A

esophagus → stratified squamous

trachea → pseudostratified squamous

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53
Q

What type of epithelium is the stomach composed of?

A

predominantly columnar epithelium mixed with other cell types like mucus producing goblet cells, parietal (acid secreting), and enterochromaffin-like (histamine secreting) cells

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54
Q

The small and large intestines are lined with what type of epithelium?

A

columnar epithelium (in addition to many different cell types)

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55
Q

The rectum has what kind of epithelium?

A

the upper part is composed of simple columnar and lower part is composed of stratified squamous non-keratinized transitioning to stratified squamous keratinized near the anal sphincter half

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56
Q

Keratinization sometimes happens due to what?

A

exposure to air

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57
Q

Why does the stomach and jejunum have more surface area than the cecum?

A

The cecum region is not as well folded so there is not as much absorption compared to the stomach and jejunum.

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58
Q

What is the role of the stomach?

A

To digest food and control the flow of its contents into the intestine → acts as a food reservoir, processes food into fluid chyme for nutrient absorption, regulates food delivery to intestine, pH protects against most bacteria which allows pepsin to function

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59
Q

What is the normal stomach pH?

A

Fasted pH in normal healthy adults is less than 3 and fed pH is in the range of 5-7

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60
Q

How long is gastric emptying half-time?

A

30 minutes

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61
Q

What is the difference between the fasted emptying cycle and the fed state cycle?

A

The fasted emptying cycles through 4 phases that culminates with a “housekeeper” wave meanwhile there is no defined cycle for the fed state

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62
Q

What are the 3 primary regions of the stomach?

A
  1. fundus
  2. body
  3. antrum
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63
Q

What is the fundus of the stomach?

A

contains gas and produces contractions to move the stomach contents (top part of the stomach)

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64
Q

What is the body of the stomach?

A

reservoir for ingested food and fluids (the middle part of the stomach)

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65
Q

What is the antrum of the stomach?

A

the lowest part of the stomach that is funnel shaped and contains the pyloric region and control the flow into the small intestine

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66
Q

What do the parietal cells of the stomach secrete?

A

HCl

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67
Q

What is prefeed?

A

the pH rises before we even eat (could be because we’re thinking about food and salivating)

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68
Q

How can different foods affect gastric emptying?

A

cold-carbonated drinks can rapidly induce gastric emptying while a Big Mac can virtually halt gastric motility

69
Q

The lower the pH…

A

the more bioavailability of the compound

70
Q

What is the transit time from the mouth to the anus?

A

24-32 hours

71
Q

What is the transit time through the small intestine?

A

3 hours

72
Q

Where does most absorption occur?

A

small intestine! where pH ranges from 5-6.5

73
Q

Where does most colon drug absorption occur?

A

in the ascending region nearest to the small intestine

74
Q

What are the characteristics of the intestine?

A
  • most transporters are located in the small intestine
  • upper small intestine is for mixing
  • lower small intestine is for electrolyte absorption
  • colon is for fluid and electrolyte absorption
75
Q

What are the characteristics of the small intestine?

A

5-6 m in length, has 3 regions: duodenum (shortest and widest 20-30 cm), jejunum (proximal 2/5), ileum (distal 3/5), composed of serosa, muscles, submucosa, mucosa (with villi and crypts), have villi

76
Q

What are the increases in surface area in the small intestine due to folding?

A

area of cylinder (1) → folds of Kerckring (х3) → villi (х30) → microvilli (х600)

77
Q

Why is the relative size of micro vs nanoparticles important?

A

Micro particles are unable to fit through the microvilli and even 480 nm particles cannot squeeze through → 120 nm particles are more able to squeeze through (but still fairly large) → nothing is absolute in science!!

78
Q

What are the different columnar epithelial cells?

A
  1. crypt cells: progenitor cells
  2. goblet cells: secrete mucus
  3. M cells: absorbs intact polypeptides and proteins, has a high metabolic capacity/rapid membrane turnover
79
Q

What type of epithelium covers each villus?

A

columnar epithelial cells form a single continuous layer over the villus → separated from lamina propria by the basal lamina which is comprised of glycoproteins and penetrable by lymphocytes

80
Q

What is the crypt region?

A

comprised of undifferentiated cells that proliferate and contains goblet cells that secrete mucus, Paneth cells that regulate microflora, and argentaffin cells that secrete mucus component

81
Q

What is the villus region?

A

Contains absorptive enterocytes, has a few goblet cells and M cells that overlay the Peyer’s patch, cells from the crypt migrate to the villus tip and are sloughed off every 2-3 days which is the lifetime of an enterocyte → the entire lining of the GI tract turns over every 2-4 days

82
Q

What does the basolateral membrane consist of?

A

located below the tight junction, no microvilli or glycocalyx, has desmosomes

83
Q

What are the characteristics of the apical membrane?

A

microvilli and brush border, protein to lipid ratio of 1.7 to 1, is a dynamic membrane, the brush border turns over more rapidly than renewal rate of cells

84
Q

What do the membrane proteins do?

A

Participate in both transport and metabolism to facilitate nutrient absorption and to prevent xenobiotic toxicity

85
Q

Lymphatic flow does not go where?

A

the liver

86
Q

About what % of cardiac output goes to the GI tract (aka digestive process)?

A

25-30%

87
Q

How many liters of blood flow to the intestinal wall?

A

40 liters/hour → 30 L/h flow to the mucosa → 19 L/h flow to the epithelial layer → only about 50% make it to the site of absorption

88
Q

Where does drug absorption and metabolism predominantly occur?

A

epithelial layer/villus enterocytes

89
Q

Where do the principal enzymes and transporters (CYP3A and pgp) reside?

A

villus enterocytes

90
Q

The muscle layer can affect what?

A

intestinal integrity and absorption

91
Q

Diseases such as IBS, IBD, Crohn’s, and camping can cause what?

A

Changes in muscle contractility which will alter GI transit time and absorption

92
Q

What is the length of the colon?

A

125 cm from the caecum to the anus (transport is much slower compared to small intestine): ascending colon is 20 cm, traverse colon is 45 cm long, and descending colon is 30 cm long → the rest is the sigmoid region

93
Q

What is the thickness of the colon?

A

Varies in thickness from 2.5 cm in the sigmoid region to 8.5 cm in the caecum

94
Q

What is the importance of the colon?

A

it is responsible for water and electrolyte absorption (caecum, ascending colon) which prevents dehydration and leads to formation of solid fecal matter

95
Q

What does the ileocaecal valve?

A

it limits food flow from the ileum into the caecum and vice versa

96
Q

What is the structure of the colon?

A
  • consists of serosa-squamous epithelium covered with adipose tissue
  • has a muscularis externa which consists of an inner circular muscle layer and an incomplete outer longitudinal layer
  • has a submucosa and mucosa
97
Q

What are the three layers of colonic mucosa?

A
  1. muscularis mucosae
  2. lamina propria
  3. epithelium
98
Q

What is the difference between the proximal and distal colon and what formulations it targets?

A

The proximal colon is where enteric coated formulations target by oral administration. The distal colon is where rectal administration target such as suppositories.

99
Q

Where do you see the most microbiome?

A

ileum and colon (example is fecal transplants)

100
Q

Where is residence time the longest?

A

colon (while esophagus is the shortest)

101
Q

Out of children, young adults, and elderly people, which age group has the longest transit time?

A

Elderly people (in all 4 regions) → and then children except for the right colon) → young adults usually had the shortest transit time

102
Q

What is the relationship between stomach emptying rates and colonic retention of the contents?

A

As stomach emptying rates decrease as time passes, the colonic retention time of the contents increase (stomach lines go downward and colonic retention increases)

103
Q

What all affects how much gets absorbed?

A

Things like the time of day and the types of meals

104
Q

What type of epithelium is the rectum composed of?

A

has an upper (simple columnar) and lower (stratified squamous non-keratinized region transitioning to stratified squamous keratinized region near anal sphincter) half → highly folded

105
Q

What is the significance of the stratified squamous, non-keratinized epithelium?

A

allows high drug absorption → there are a number of high potency drugs that can be delivered rectally

106
Q

What is the significance of delivering drugs rectally?

A

many young and old patients cannot swallow pills so then extemporaneous compounding of the drug in suppositories is used → also has a low residence time

107
Q

What are the 3 sources of variability in drug response?

A
  1. genetic factors → drug targets, drug transporters, drug metabolizing enzymes
  2. environmental factors → induction and inhibition
  3. physiological factors → age and disease
108
Q

Once a drug breaks down into smaller particles, the smaller the particle, the more likely it will be…

A

wet → more surface area to be wet, the more likely to get more drug into the solution

109
Q

After the dissolution process, what are the 2 forms?

A
  1. crystalline form → low solubility

2. amorphous → increased solubility

110
Q

What will eventually get through the membrane?

A

the free API (active pharmaceutical ingredient)

111
Q

What are some examples of potential confounders?

A

food, pH, protein binding

112
Q

What is the mean residence time?

A

3.45 hours (but varies from 0.87 hours to 9.5 hours)

113
Q

What does biorelevant mean?

A

how closely do we mimic biology/physiology

114
Q

For the same batch of non-disintegrating pellets, is there significant variation?

A

Yes → there is a significant variation of intra-individual small intestinal transit times

115
Q

What is the importance of the study of the plasma levels of 4-amino-salicylic acid (4-ASA) in 2 different patients after ingestion of an enteric coated capsule?

A
  1. gastric residence differs dramatically
  2. gastric emptying controls colonic absorption where greater GI residence leads to higher absorption
  3. Patient 2 had a significantly faster GI transit-capsule voided in less than 6 hours (compared to patient 1 that took longer)
116
Q

Where does the fed state pH stay around?

A

pH of 3-4

117
Q

What is the pH difference between the jejunum, ileum, and colon?

A

jejunum (7.08), ileum (7.8), colon (8.1)

118
Q

Where is bile salt content found when there’s a problem?

A

jejunum

119
Q

When sequestered in a micelle, what happens?

A

Can be taken up as a lipid droplet so that not only the free drug is sequestered (gets across)

120
Q

The amount of buffer capacity can change what?

A

pH and the fraction of ionized/unionized

121
Q

More unionized is likely to get through the membrane using what process?

A

Passive transcellular diffusion

122
Q

More ionized means what?

A

Less likely to get through the membrane and less likely to get absorbed

123
Q

What are the 5 factors that can influence drug solubility?

A
  1. buffer capacity
  2. bile salts
  3. regional fluids
  4. other drugs
  5. potential issues from endogenous substrates
124
Q

The GI tract can be divided into what smaller areas?

A

duodenum → jejunum I → jejunum II → ileum I → ileum II → ileum III → ileum IV → colon

125
Q

Why do one size formulations do not fit all?

A
  1. transporters and enzymes vary along the GI tract
  2. variability in GI fluid composition
  3. diet and chemical exposure varies
  4. drug-drug and drug-nutrient interactions occur
  5. pharmacogentics and genomics are big issues
126
Q

Disposition consists of what?

A

distribution and elimination

127
Q

Elimination includes both what?

A

metabolism and excretion

128
Q

Toxicity results from what?

A

exposure

129
Q

ADME can be defined by what?

A

Plasma vs. time curves → can also be used for bioequivalence

130
Q

What is the major role of metabolism?

A

To make the compound more polar so it can be more easily excreted in the bile or urine (making lipophilic compounds more polar)

131
Q

Once a drug is ingested, what can happen?

A

dissolution, degradation, or absorption

132
Q

Humans are treated as what?

A

one compartment model → individual organs can be separated and modeled based on kinetics

133
Q

How is the nature of pharmacokinetic processes described by?

A

Concentration time profiles in which the shape of the profiles depends on point of observation → compartments represent kinetically similar tissues or spaces in which processes can be reversible/irreversible or linear/nonlinear → fast and slow processes disappear

134
Q

What is the Tmax?

A

the time to reach the maximum blood/plasma concentration from a dosage form

135
Q

What is Cmax?

A

the maximum blood/plasma concentration from a dosage form

136
Q

What is bioavailability?

A

refers to the rate and extent of drug absorption

137
Q

What is absolute bioavailability?

A

AUC of a given dosage form compared with the AUC of the same dose injected intravenously

138
Q

What is relative bioavailability?

A

refers to the AUC of a given dosage form compared to an arbitrary reference standard

139
Q

Bioequivalent does not mean what?

A

that the therapeutic effect of two dosage forms are equivalent → so not therapeutically equivalent!!

140
Q

What is the Paracelsian theory?

A

A chemical might have no effect on an organism, a beneficial effect, or a toxic effect

141
Q

What is the most important factor in pharma and toxicology?

A

The dose-response relationship

142
Q

What 2 aspects does dose cover?

A
  1. the amount of chemical in which the whole organism is treated
  2. the local concentration of the chemical at the biological response site
143
Q

What is a function of ADME?

A

The relationship between dose and receptor concentration

144
Q

What goes into consideration for the dose?

A
  1. physicochemical properties of the compound
  2. physiological factors
  3. formulation factors
  4. will lead to being safe and efficacious
145
Q

The absorption rate is controlled by what?

A

formulation parameters that are optimized to provide a Cmax and Tmax associated with a safe and efficacious response in the patient

146
Q

What is the difference between MTL and MEL?

A 
MTL = minimum toxic level
MEL = minimum effective level
147
Q

Prolonged exposure to subtherapeutic doses or ineffective drugs can lead to what?

A

the development of the disease becoming worse → above the MTC can be harmful

148
Q

For multiple dosing and accumulation, what do we want to do?

A

Want frequency near the value between MTC and MEC near the Cpss value (plasma concentration at steady state)

149
Q

What happens when AUC is above MTC, in the TW, and below the MEC?

A

Above MTC = toxic response
In TW = safe and efficacious
Below MEC = not efficacious

150
Q

What do coatings do?

A

Control diffusion rates and modify the release properties of the drug from the interior

151
Q

What do disintegrants do?

A

Control regions of release based on physicochemical properties

152
Q

What do lubricants do?

A

Slow dissolution based on properties

153
Q

How do internal excipients modify release rates?

A

swellable matrices, non-swelling matrices, inert plastics

154
Q

Coatings are applied to the outside of solid dosage forms to do what?

A
  1. protection of agent from air and/or humidity
  2. mask taste
  3. provide special drug release
  4. aesthetics
  5. prevent inadvertent contact with the drug (ex. proscar and pregnant women)
155
Q

Aqueous film coatings contain the following:

A
  1. film-forming polymer
  2. plasticizer to produce flexibility and elasticity of coating
  3. colorant and opafier
  4. vehicle
156
Q

Non-aqueous film coatings usually contain the following:

A
  1. film-forming polymer to produce smooth films
  2. provide water solubility or permeability to the film
  3. plasticizer to produce flexibility and elasticity
  4. surfactants to enhance film coat spreading
  5. colorant and opafier to improve appearance
  6. sweeteners, flavors, and aromas
  7. glossant to provide luster
  8. volatile solvent to allow spreading and evaporation
157
Q

What is the purpose of enteric coatings?

A

added to dosage forms to prevent the early release of an API in a region where it may undergo chemical or metabolic breakdown

158
Q

What are the primary reasons for enteric coatings?

A
  1. prevent acid sensitive APIs from gastric fluids
  2. to prevent gastric distress from the API
  3. to target API delivery to a site in the intestine
  4. to provide a delayed/sustained release
  5. to deliver the API in a higher local concentration in the intestines where it may be absorbed and have higher bioavailability
159
Q

What is sustained release?

A

slow the release of a therapeutic agent so that its appearance in the systemic circulation is delayed/prolonged and is plasma profile is sustained in duration → onset of pharmacologic action is delayed but its therapeutic effect has a sustained duration

160
Q

What is controlled release?

A

implies a reproducibility and predictability in the drug release kinetics → allows us to maintain a narrow drug plasma concentration steady state

161
Q

What are examples of coated beads, granules, or microspheres?

A

coating on the beads controls release by programmed erosion → an example would be contact

162
Q

What is an example of the multitablet system?

A

small tablets placed in a gelatin capsule

163
Q

What is an example of a microencapsulated formulation?

A

solids, liquids, or gases that are encapsulated into walled material which allows spreading of microparticles across absorbing surfaces

164
Q

What does drug embedding in a slowly eroding or hydrophilic matrix mean?

A

the drug is homogenously dispersed in the eroding matrix and its release is controlled by erosion rate

165
Q

At steady state, the levels achieved depend on what?

A
  1. clearance
  2. volume of distribution
  3. dose
  4. dosing interval
166
Q

A drug with a lower K has what?

A

longer t 1/2 → so a drug with a higher K has a shorter t 1/2

167
Q

At steady state, the rate doing into the body must equal what?

A

the disposition (the rate distributing early and being metabolized and/or being excreted from the body throughout)

168
Q

What are the characteristics of drugs that are best suited for oral controlled release formulations?

A
  1. exhibit neither slow or fast rates of absorption and excretion
  2. uniformly absorbed from the gastrointestinal tract
  3. administered in relatively small doses
  4. have good safety/therapeutic window
  5. chronic therapies are better suited than acute

Dosage Forms (5 decks)

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