Oral Solid Dosage Forms

Question 1

What are oral solid dosage forms?

Answer 1

Medicinal products delivered via the mouth in a solid form. Absorbed via the GI system or oral cavity in tablet or capsule form

Question 2

What size are coarse powder particles?

Answer 2

> 1000μm

Question 2

What size are intermediate powder particles?

Answer 2

> 100μm <1000μm

Question 3

What size are fine powder particles?

Answer 3

> 5μm and <100μm

Question 4

What size are ultrafine powder particles?

Answer 4

<5μm

Question 5

What are ultrafine powders usually used for?

Answer 5

Inhaled substances

Question 6

How does particle shape affect powder flow?

Answer 6

Spherical particles have good flow
Acicular (needlelike) particles have poor flow

Question 7

What happens to large, non-spherical and low density particles when shaken?

Answer 7

They move up

Question 8

What are light-based methods of particle size analysis?

Answer 8

Light microscopy - only for particles visible to the naked eye
Scanning or transmission electron microscopes - for ultrafine particles

Question 9

What is used for laser light diffraction?

Answer 9

Malvern Mastesizer for particles sized 0.5-3500μm

Question 10

What is used for photo correlation spectroscopy?

Answer 10

Malvern Zetasizer for particles 0.3nm-10μm

Question 11

What is Air Jet Sieving?

Answer 11

Using pulses of air and vacuum to alternatively push and pull particles off and onto a screen
All particles that pass through are removed and the remainder are transferred to a larger aperture screen to repeat the process
Only used for very fine powders and brittle products

Question 11

What are the different sieving methods?

Answer 11

Stack of sieves
Air Jet sieving
Inertial impaction

Question 12

What is Inertial Impaction?

Answer 12

Used for inhalation-based products due to similarity of method of drug delivery to the lungs

Question 13

How is time of flight measured in inhaled products?

Answer 13

Malvern Aerosizer
Electrical Steam Sensing Zone Method - Coulter counter
Sedimentation method -

Question 14

How does a Malvern Aerosizer work?

Answer 14

Time of passage between 2 laser beams

Question 15

How does the Electrical Steam Sensing Zone Method work?

Answer 15

Monitors change of electrical signal which occurs as a particle passes through the orifice

Question 16

How does Sedimentation method work?

Answer 16

Uses Stoke’s Law and Reynold’s number to determine particle size based on time taken to settle in fluid of known viscosity

Question 17

Why are equivalent spheres needed?

Answer 17

All particle shapes other than a sphere will have multiple measurements which can be taken as particle size

Question 18

What are 2 types of equivalent sphere?

Answer 18

Equivalent sphere of volume of particle
Equivalent sphere of length of particle

Question 19

What is dynamic sampling?

Answer 19

Take a proportion when product is in motion

Question 20

What is static sampling?

Answer 20

Take a sample when the product is at rest

Question 21

Why is static sampling not as favourable as dynamic sampling of powders?

Answer 21

Some level of aggregation must have occured so is not as truly representative as dynamic sampling

Question 22

What is adhesion in powder flow?

Answer 22

2 chemically dissimilar materials stick together

Question 23

What is cohesion in powder flow?

Answer 23

2 chemically similar materials stick together

Question 24

What is mechanical force in powder flow?

Answer 24

Particles become interlocked due to shape and surface roughness

Question 25

What is capillary force in powder flow?

Answer 25

Occurs due to adsorbed liquids on the surface of particles trying to minimise their surface area

Question 26

What does powder flow depend on?

Answer 26

The balance between adhesion and cohesion, and forces promoting flow such as gravity and applied stress

Question 27

What is the angle of repose?

Answer 27

Maximum angle to the horizontal made by a static heap of powder

Question 28

How is the angle of repose increased?

Answer 28

Smaller particle size, increased surface roughness and increased moisture content of the powder

Question 29

What is bulk density of a powder?

Answer 29

Density of a powder taking into account its packing fraction (k) and can be measured by tapping

Question 30

What is bed porosity?

Answer 30

Percentage of volume taken up by air

Question 31

What is Hausner's ratio?

Answer 31

The ratio of tapped bulk density to poured bulk density

Question 32

What does a value of >1.5 for Hasuner's ratio indicate?

Answer 32

A cohesive powder with poor flow

Question 33

What is Carr's Compression Ratio?

Answer 33

(tapped BD-poured BD/tapped BD) x100

Question 34

What does a Carr's Compression Ratio of less than 10 indicate?

Answer 34

Excellent flow

Question 35

What does a Carr's Compression Ratio of more than 20 indicate?

Answer 35

Poor flow

Question 36

What is powder mixing?

Answer 36

A unit operation that aims to treat two or more components initially in an unmixed or partly mixed state so that each unit of component lies nearly as possible in contact with a unit of each of the other components

Question 37

What is trituration?

Answer 37

Mixing with mortar and pestle

Question 38

What is percolation segregation?

Answer 38

Seperation of mixed particles according to size

Question 39

What is trajectory segregation?

Answer 39

Mass based seperation

Question 40

What is elutrication segregation?

Answer 40

Small and low density particles become entrained within the air flow when particles are mixed so they settle at the bottom

Question 41

What is a positive mixture?

Answer 41

Equal mixing on a molecular level that is irreversible

Question 42

What is a negative mixture?

Answer 42

Sponatneous segregation occurs due to differences in density, size and shape

Question 43

What is a neutral mixture?

Answer 43

No movement without the addition of energy and applies to most powders

Question 44

What is the scale of scrutiny equation?

Answer 44

(unit dose/conc in blend) x100 Usually equal to the weight/volume of a unit dose

Question 45

What is comminution?

Answer 45

Reducing large solid masses into smaller units by mechanical means

Question 46

Why is comminution done?

Answer 46

To improve production efficiency To improve improve aesthetics and stability of ointments, creams and suspensions Can optimise dissolution rate

Question 47

What are problems with comminution?

Answer 47

Product aggregation Product degradation Polymorphic changes Contamination Alteration of moisture content