Routes Of Administration Oral (Tablets) Flashcards
(30 cards)
1
Q
What is the pH in the stomach and transit time?
A
- pH (fasted) 1/2, pH (fed) 4/5
- 0/3 hr
2
Q
What is the pH and transit time in the small intestine
A
- pH 5/7
- 3/4 hr
3
Q
What is the pH and transit time in the large intestine?
A
- pH 6/7.5
- transit time highly variable
4
Q
What are the advantages of the oral route?
A
- Most common route
- Simplest / convenient
- Modified release formulations available
- High Surface area with good absorptive capacity
5
Q
What are the Oral route advantages?
A
- Most common route
- Simplest, convenient, safe
- Modified release formulations available
- High surface area with good absorptive capacity
6
Q
What are the Oral route disadvantages?
A
- Slower onset of action (dissolution is the rate limiting step)
- Variable absorption (changes with age, gender)
- Hostile environment (GI secretions, enzymes)
- First pass metabolism
- Difficult to reverse therapy
- GI irritation
7
Q
What is the British pharmacopeia’s definition of a tablet?
A
- Are solid preparations each containing a single dose of 1 or more active substances
- Obtained by compressing uniform volumes of particles
- Tablets are intended for Oral Administration (some are swallowed whole, chewed, dissolved, dispersed or retained
8
Q
What are the advantages of Tablets?
A
- Convenient to take and handle
- Better chemical, physical and microbiological stability compared to liquids (better shelf life)
- Precise dosing of drug
- Relatively cheap to mass produce with consistent quality
9
Q
What do all tablets need to be?
A
- Include the correct dose of drug
- Be consistent in weight, size
- Release drug in controlled and reproducible manner
- Be biocompatible and not harm patients
- Be of sufficient mechanical strength
- Be chemically, physically, and microbiological stable
10
Q
What are the different types of tablets?
A
- Disintegrating
- Gastro resistant
- Modified release
- Dispersible
- Effervescent
- Sublingual and Buccal
- Lozenges and Pastilles
11
Q
What is the disintegrating tablet?
A
- Most common type
- Swallowed and released in a short time
- Excipients used are not intended to modify the drug release profile. Can be coated or uncoated
12
Q
What are gastro resistant tablets?
A
- They are delayed release tablets
- Intended to resist the gastric fluid and to release the drug in the intestinal fluid
- Prepared by covering the tablets with gastro resistant coating
13
Q
What are modified release tablets?
A
- Coated or uncoated tablets that contain special excipients and prepared by special procedures to modify rate or place
- Normally swallowed whole
—Prolonged release : drug released slowly at a constant rate
—Delayed release : drug is released some time after Administration
—Pulsatile release : drug is released from the formulation in 2 or more pulses
14
Q
What are dispersible tablets?
A
- Can be coated or uncoated intended to be dispersed in water before Oral Administration
- Orodispersible tablets are uncoated tablets intended to be placed in the mouth where they disperse before swallowed
- Soluble tablets can be uncoated or film coated intended to be dissolved in water before Administration
15
Q
What are effervescent tablets?
A
- They are uncoated tablets intended to be dissolved or dispersed in water before Administration
- Containing a weak acid and a carbonate/ bicarbonate which react rapidly in the presence of water to release CO2
- High carbonate results in a buffer solution temporarily increases stomach pH
- Leads to fast emptying of stomach content
- Allows drugs to enter the intestine faster for absorption
- Provides a faster drug absorption and minimise stomach irritation
16
Q
What are sublingual tablets?
A
- Are placed under the tongue
- Small and porous - rapid drug release for systemic effect without first pass liver metabolism
17
Q
What are buccal tablets
A
- Placed in the buccal cavity (the side of the cheek)
- High up between the inside of the upper lip and gum
- Provide rapid drug release for systemic effect without first pass liver metabolism
18
Q
What are lozenges and pastilles?
A
- Solid, single dose preparations
- Lozenges are hard whereas pastilles are soft, flexible
- Intended to dissolve or disintegrate slowly in the mouth when sucked (usually for local effect)
19
Q
What are the stages of tablet formation?
A
- Die filling (powder flows down from hopper into a die)
- Tablet formation - upper punch compresses powder into tablet (compression) upper punch moves upward (decompression)
- Tablet ejection - lower punch rises to eject the tablet and a pushing device removes tablet from the die
20
Q
What is the single punch press?
A
- Consists of 1 die and 1 pair of punches
- Lower punch is stationary, pressure applied
- Produces 200 tablets per minute
21
Q
What is the rotators press?
A
- Multi station presses
- Upto 10,000 per minute
- Multiple sets of punches and dies
- Dies and punches both rotate together
22
Q
What are the different designs of tablets
A
- Shapes: circular, oval, oblong, triangular
- Side view: flat or convex (bevelled edges)
- Break marks: Breaking for reproducible doses
- Markings: embossed, debossed
23
Q
What are the important properties of a powder mix?
A
- Homogeneity and segregation tendency (Under/ over mixing)
- Flowability (controlled by gravity)
- Compression and compaction
- Friction and adhesive properties
24
Q
What are the commonly used excipients?
A
- Filler
- Disintegrant
- Binder
- Anti-adherent
- Lubricant
- Glidant
25
Why is a filler added to tablets?
- Increase the bulk volume of powder and tablet size for ease of handling
- Lactose is a common tablet filler
26
Why is disintegrant added to the tablets?
- Allows tablet to break up into small fragments when in contact with liquid
- Promotes rapid drug dissolution thus bioavailability
- Starch is commonly used
27
Why is the binder added to the tablet?
- Ensures granules and tablets can be formed with the required mechanical strength
- starch, cellulose
28
Why is glidant added to the tablet?
- To improve powder flowability by reducing cohesion between particles
- Talc, colloidal silica
29
Why is lubricant added to the tablet?
- It lowers friction between the solid ingredients and the machine wall
- It improves tablet formation and ejection
- Magnesium stéarate is most widely used
30
Why is anti-adherent added to tablets?
- Reduces adhesion between powder and punch faces
- Prevents particles sticking to the punches
- Particularly important if tablet punches have markings
- Starch, cellulose
