Oral Drug and Controlled Release Delivery

Question 1

What are the advantages of an oral drug delivery system?

Answer 1

It is effective, accurate, convenient and cost effective

Question 2

List the shortcomings of oral drugs.

Answer 2

Variability in GI environment
Bioavailability
Limited drug targeting
Pediatric/ geriatric population difficulties

Question 3

What are the absorption sites with oral dosages?

Answer 3

Stomach (limited)
Small intestine(primary site)
Large intestine(v. limited)
Mouth (buccal and sublingual)
Rectum

Question 4

What are the 3 key drug properties that need to be considered in oral formulations?

Answer 4

Absorption
Stability
Processing

Question 5

What is the most critical issue for preparation and delivery?

Answer 5

Solubility

Question 6

What is the benefit and downside of solutions?

Answer 6

Increases drug absorption but is less stable

Question 7

What does effect does particle size have on solubility?

Answer 7

Increases surface area

Faster disintegration/dissolution

Question 8

How do we ensure stability in vitro?

Answer 8

Coating (tablets and capsules if not stable to light, moisture, etc)
Excipients
Protective packaging

Question 9

How do we ensure stability in vivo?

Answer 9

Enteric coating
Controlled/sustained release
Site- specific release

Question 10

What are some ways to increase absorption?

Answer 10

Improve solubility
Increase disintegration and dissolution
Administration strategies (w/out food: absorbed quickly and excreted quickly, better to take with food even though slower absorption)

Question 11

What are some strategies to deal with metabolism?

Answer 11

Dose increase
Pro drugs
Enzyme inhibitors
Other administration routes

Question 12

Where is drug targeting limited to in oral delivery?

Answer 12

The GI tract

Question 13

How is drug targeting achieved?

Answer 13

Adhesive polymers to stomach

Sustained/controlled release to small intestine

Question 14

What are 4 common mucoadhesive polymers (hydrophilic gels)?

Answer 14

Chitosans
Polyacrylates
Polyglucons
Hyaluronans

Question 15

What do mucoadhesive polymers do?

Answer 15

Prolong residence
Increase contact time and bioavailability
Localization in specific residence

Question 16

Who utilizes oral solutions?

Answer 16

Pediatrics and elderly

Question 17

What are the two important considerations that must be accounted for in oral solutions?

Answer 17

Taste and colour

Additives(alcohol, sugar, preservatives)

Question 18

Name the 3 absorptive sites of quick dissolving formulations.

Answer 18

Oral
Buccal
Sublingual

Question 19

What are the benefits of quick dissolving formulations?

Answer 19

Fast drug release
Little liquid needed
Convenient administration

Question 20

Why do quick dissolving drugs need special packaging?

Answer 20

They can’t be exposed to moisture

Question 21

What are some drugs that can be found as quick dissolving and why?

Answer 21

Analgesics, antihistamines, migraine, antidepressants, Parkinsons
Want quick onset or there is a difficulty in taking medications

Question 22

Common excipients used in quick dissolving solutions.

Answer 22

Mannitol, sorbitol, effervescent ingredients

Question 23

What are the 4 methods of forming quick dissolving tablets?

Answer 23

Spray drying, molding, wet granulation, compression

Question 24

What are some ways to taste mask?

Answer 24

Additive-dilution
Film coating
Melting with lipid-based excipients

Question 25

These devices can be inserted and a slow release of drug occurs.

Answer 25

Controlled release

Question 26

What are the benefits of controlled release?

Answer 26

Fewer administrations Steady blood concentrations Better therapeutic outcome Improved patient compliance

Question 27

What are the 3 types of controlled release drugs?

Answer 27

Delayed release Controlled release Targeted release

Question 28

Release of two successive doses, initial plus replenishment.

Answer 28

Delayed release

Question 29

Drug release over a long period of time, independent of external factors or envornment.

Answer 29

Controlled release

Question 30

Site specific or receptor specific. | Sophisticated dosage forms, normally in Parenteral formulations

Answer 30

Targeted release

Question 31

What are the benefits of targeted release?

Answer 31

Smaller drug dose, fewer dosing, less potential SE, better compliance

Question 32

What are the drawbacks of controlled release?

Answer 32

"Dose dumping" potential Difficult dosing termination Variable absorption due to varying GI interactions Increased production cost

Question 33

What are three conditions that controlled release is appropriate for?

Answer 33

Cardiovascular Respiratory Mood control

Question 34

What is the optimal half life of a drug to be a controlled release candidates?

Answer 34

2-8hrs Any shorter and we need to increase drug dose Any longer and there's no need for it Longer than 8 hrs and drug will be in large intestine (no absorption)

Question 35

What is the optimal dosing range for controlled release drugs?

Answer 35

0.5g- 1.0g, preferably less than 0.5g

Question 36

pH range of stability with controlled drugs?

Answer 36

1-8

Question 37

What are the 4 drug release mechanisms?

Answer 37

Diffusion controlled Dissolution/Diffusion controlled Dissolution controlled Osmotic Pressure controlled

Question 38

Does diffusion or dissolution play a more significant role in drug release?

Answer 38

Dissolution

Question 39

Describe the Reservoir System.

Answer 39

There is a drug core and the release rate is controlled by film properties: polymers(how fast it dissolve/how permeable to water it is) There is a potential for toxicity if coating is accident lay destroyed.

Question 40

Describe the Matrix System.

Answer 40

Drug and polymer is mixed, release rate is controlled by polymer. This is more of a diffusion method vs dissolution.

Question 41

This system is cheaper and allows for the delivery of larger molecules but zero order delivery livery is impossible

Answer 41

Matrix system

Question 42

This system is harder to control due to dissolution and diffusion release rates and the rates being dependant on shape of dosage form

Answer 42

Bioerodible System (matrix)

Question 43

The release rate is controlled by the drug or the polymer?

Answer 43

Can be controlled by either or both.

Question 44

Describe osmotic pumps.

Answer 44

Coated tablet with semipermeable membrane, containing unique chemical in the core that creates osmotic pressure. Drug release is independant of environment

Question 45

Pressure produced by separate chemical cause what kind of order release?

Answer 45

Zero

Question 46

What are the 4 things quality control is watching for in controlled release drugs.

Answer 46

Drug content Drug uniformity Disintegration Dissolution