L51: Solid dosage forms- the roles of excipients

Question 1

What are excipients?

Answer 1

Substances included in a drug formulation other than the active pharmaceutical ingredient (API).

Question 2

Why are excipients important in pharmaceutical formulations?

Answer 2

They ensure product performance, manufacturability, stability, and patient acceptability.

Question 3

Do excipients affect the effectiveness of the medicine?

Answer 3

Yes, they can affect drug release, stability, and absorption.

Question 4

What are three major roles that excipients perform in solid dosage forms?

Answer 4

Acting as fillers (diluents), binders, and disintegrants.

Question 5

Can one excipient serve more than one function?

Answer 5

Yes, some excipients can have multifunctional roles.

Question 6

What are some ideal characteristics of excipients?

Answer 6

They should be chemically stable, non-toxic, pharmacologically inactive, and compatible with the drug.

Question 7

Why is compatibility with the API important in excipient selection?

Answer 7

To prevent chemical or physical interactions that may compromise the drug’s safety or efficacy.

Question 8

How are excipients commonly classified?

Answer 8

Based on their function, such as diluents, binders, disintegrants, lubricants, glidants, etc.

Question 9

Name four common functional categories of excipients.

Answer 9

Diluents, binders, disintegrants, and lubricants.

Question 10

What is the purpose of a diluent in tablet formulation?

Answer 10

To increase bulk and enable accurate dosage when the amount of API is small.

Question 11

Give two examples of commonly used diluents.

Answer 11

Lactose and microcrystalline cellulose.

Question 12

What role do binders play in solid dosage forms?

Answer 12

They help hold the formulation together by promoting particle adhesion.

Question 13

What are examples of binders?

Answer 13

Starch paste, gelatin, and polyvinylpyrrolidone (PVP).

Question 14

What is the purpose of disintegrants in tablets?

Answer 14

To facilitate the breakup of tablets into smaller fragments upon ingestion, aiding dissolution.

Question 15

How do disintegrants typically work?

Answer 15

By swelling when in contact with water, pushing particles apart.

Question 16

Name two commonly used disintegrants.

Answer 16

Croscarmellose sodium and sodium starch glycolate.

Question 17

Why are lubricants important in tablet manufacturing?

Answer 17

They reduce friction between the tablet and the die during compression and ejection.

Question 18

Give examples of common lubricants.

Answer 18

Magnesium stearate and stearic acid.

Question 19

What is the function of glidants in tablet production?

Answer 19

To enhance the flow properties of the powder or granules.

Question 20

Provide an example of a glidant.

Answer 20

Colloidal silicon dioxide.

Question 21

Why are colouring agents used in solid dosage forms?

Answer 21

For aesthetic purposes, identification, and brand differentiation.

Question 22

What is the main role of flavours and sweeteners in oral solid dosage forms?

Answer 22

To improve taste and patient compliance, especially in chewable or dispersible tablets.

Question 23

What are preservatives used for in tablet formulations?

Answer 23

To prevent microbial growth.

Question 24

What do antioxidants prevent in solid dosage forms?

Answer 24

They prevent degradation due to oxidation.

Question 25

What are the three main methods used in tablet manufacturing?

Answer 25

Wet granulation, dry granulation, and direct compression.

Question 26

What is wet granulation?

Answer 26

A process where powders are bound using a liquid solution to form granules before compression.

Question 27

Why is wet granulation used?

Answer 27

To improve flowability and compressibility of powders.

Question 28

When is dry granulation preferred over wet granulation?

Answer 28

When the drug is sensitive to moisture or heat.

Question 29

How is dry granulation typically achieved?

Answer 29

By compressing the powder into slugs or roller-compacting it, then milling.

Question 30

What is the key requirement for direct compression to be successful?

Answer 30

Both the API and excipients must have excellent flow and compressibility.

Question 31

What is a major advantage of direct compression?

Answer 31

It is a faster and simpler process with fewer steps.

Question 32

How can excipients affect drug release?

Answer 32

They can influence disintegration, dissolution rate, and bioavailability.

Question 33

Why is it important to assess drug-excipient compatibility?

Answer 33

To ensure there are no interactions that compromise drug stability or effectiveness.

Question 34

What are three methods used to evaluate drug-excipient compatibility?

Answer 34

Differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction.

Question 35

What do regulatory bodies require in terms of excipient documentation?

Answer 35

Evidence of safety, consistency, and justification for excipient use.

Question 36

What does GRAS mean?

Answer 36

Generally Recognized As Safe – a regulatory classification for excipients with proven safety profiles.

Question 37

Why is functionality testing of excipients necessary?

Answer 37

To ensure they perform consistently in the final formulation.

Question 38

What four key factors should guide excipient selection?

Answer 38

Functionality, compatibility with API, safety, and regulatory compliance.

Question 39

What is the main takeaway regarding excipients in solid dosage forms?

Answer 39

Excipients are essential for successful formulation and are not inert; they must be carefully selected and tested.