Solid Dosage Forms I

Question 1

What is a dosage form?

Answer 1

It is the physical form by which drug molecules are delivered to their site of action.

Question 2

What are solid dosage forms?

Answer 2

Solid dosage forms are dosage forms which are solid in physical
form.

They are made up of an active pharmaceutical ingredient
or a combination of active pharmaceutical ingredients and
excipients, most of which occur in solid state.

Question 3

What is a powder?

Answer 3

A pharmaceutical powder is defined as a dry, solid dosage form, composed of finely divided drugs with or without excipients and intended for internal or external use

Question 4

What are the 2 forms in which powders may exist?

Answer 4

• Crystalline
• Amorphous

Question 5

Mention 5 chemical and physical features used to characterise powders.

Answer 5

1. Morphology
2. Purity
3. Solubility
4. Flow properties
5. Bulk and tapped densities
6. Particle size
7. Compatibility with other formulation components.

Question 6

Mention 4 advantages of powders.

Answer 6

1. Better physicochemical stability than liquid dosage forms.
2. Suitable for children or adults who have difficulty swallowing capsules and tablets.
3. Effective for providing larger dose than other dosage forms
4. Mixing of multiple medical agents provides great versatility to the medicine through therapeutic synergy

Question 7

Mention 4 disadvantages of powders.

Answer 7

1. Drugs with unpleasant taste are difficult to consume in powder form.
2. Powdered medicine is heavy and bulky
3. Hygroscopic drugs cannot be dispensed in powdered form
4. May not be suitable for oral administration where the medicine my harm the stomach or be inactivated in the stomach.

Question 8

What are the processes involved in the preparation of powders?

Answer 8

i. Particle size reduction
ii. Sieving
iii. Weighing each ingredient
iv. Mixing
v. Packaging

Question 9

Size reduction is also called:

Answer 9

• Comminution
• Pulverization
• Grinding

Question 10

Mention 4 methods of large-scale size reduction with examples.

Answer 10

1. Compression: Application of positive pressure e.g. ball mill.
2. Impact: Hitting stationary material e.g. hammer mill
3. Shear: cutting force e.g. colloid mill
4. Attrition: breaking the edges of the solid by impact or particle collision e.g roller mill, fluid energy mill

Question 11

Mention 4 methods of mixing powders.

Answer 11

1. Spatulation
2. Trituration
3. Geometric dilution
4. Tumbling

Question 12

Spatulation is suitable for large quantities of powders or for powders containing one or more potent substances.

True or False

Answer 12

False.
It is not suitable because homogenous blending may not occur.

Question 13

Which mixing method is most suitable when potent substances are to be mixed with large amounts of diluent?

Answer 13

Geometric dilution.

Question 14

How are powders to be packaged?

Answer 14

Powders may be wrapped in paper or dispensed in bulk powder in a wide
mouth container.

Question 15

Mention 6 types of powders.

Answer 15

1. Bulk powder
2. Insufflations
3. Powder sprays
4. Effervescent powder
5. Divided powders
6. Dusting powder
7. Douche powder
8. Dentifrices

BIPED4

Question 16

How are bulk powders packaged?

Answer 16

They are supplied in wide-mouthed containers that permit easy removal of a spoonful powder.

Question 17

The major problem with bulk powders is inaccuracy of dose. Mention 2 factors that may affect dosage.

Answer 17

1. Measuring spoon
2. Humidity

Question 18

How are dusting powders packaged?

Answer 18

In a glass/metal container with a perforated lid (sifter top containers)
to allow powders be dusted to the affected area.

Question 19

Differentiate between the 2 categories of dusting powders.

Answer 19

Surgical powders are used mainly in body cavities, on burns and umbilical cords of infants as a result of major wounds

Medical dusting powders are used for superficial skin conditions.

Question 20

What are the most common ingredients used in dusting powders? Why are they used?

Answer 20

Talc and Kaolin.
They are inert.

Question 21

Mention 5 uses of dusting powders.

Answer 21

1. Antiseptic
2. Astringent
3. Absorbent
4. Antipruritic
5. Antiperspirant

Question 22

What is a douche powder?

Answer 22

Douche powder is a powder drug that is used for the cleaning solutions of intimate body parts for hygiene.
They are kept in metal foil bags.

Question 23

What are insufflations?

Answer 23

Insufflations are extremely small particles of pharmaceutical powders to be injected into the body cavities.

Insufflations are medicated dusting powder meant for introduction into body
cavities such as, nose, throat, ears and vagina with the help of an apparatus
“Insufflator” .

Question 24

What are divided powders?

Answer 24

Divided powders, or chartulae, are single doses of powdered drug mixtures individually enclosed in paper, plastic laminates, or metallic foil wrappers or packets e.g. powdered laxatives.

Question 25

What are the two components necessary for the evolution of gas in effervescent powders?

Answer 25

i. A soluble carbonate e.g. sodium bicarbonate ii. An organic acid e.g. citric acid, tartaric acid

Question 26

What are tablets?

Answer 26

Tablets are solid unit dosage forms of medicaments, with or without suitable excipients, prepared by molding or compression.

Question 26

Mention 5 advantages of tablets.

Answer 26

1. Easy to swallow 2. Easy to carry 3. Easy and cheap to package and transport 4. Suited to large-scale production 5. Pharmaceutical elegance 6. Unpleasant taste may be masked by sugar coating 7. Easy to dispense and control by pharmacists 8. Formulation of special release profile drugs

Question 27

Mention 3 disadvantages of tablets

Answer 27

1. Some drugs are resistant to compression 2. Drugs with poor wetting or dissolution may be hard to formulate 3. Drugs that are sensitive to oxygen or moisture may require encapsulation before compression.

Question 28

What are the properties of a good tablet?

Answer 28

i. Elegant ii. Free of defects iii. Chemically and physically stable iv. Predictable and reproducible drug release

Question 29

Mention 5 types of tablets.

Answer 29

1. Compressed tablets 2. Sugar-coated tablets 3. Enteric-coated tablets 4. Film-coated tablets 5. Chewable tablets 6. Effervescent tablets 7. Matrix tablets 8. Sublingual tablets

Question 30

What are the excipients added in the formulation of tablets by direct compression?

Answer 30

i. diluent ii. Compression aid iii. Disintegrant iv. Lubricants and glidants

Question 31

Mention 3 methods used in the preparation of tablets.

Answer 31

1. Direct compression 2. Dry granulation 3. Wet granulation

Question 32

The materials may be compressed directly if they have:

Answer 32

i. crystalline properties ii. Free flowing properties iii. Binding characteristics

Question 33

Briefly describe the two methods of granulation.

Answer 33

Dry granulation: make use of roller compaction or slugging to achieve agglomeration. Wet granulation: Use granulation liquid with or without binder to achieve agglomeration.

Question 34

Mention 5 technological innovations of wet granulation.

Answer 34

1. Steam granulation 2. Moist granulation 3. Thermal granulation 4. Melt granulation 5. Freeze granulation 6. Foam granulation 7. Reverse wet granulation

Question 35

What are the factors that should be taken into consideration when formulating tablets?

Answer 35

i. Drug dose ii. Excipients iii. Compression pressure iv. Friability v. Appearance vi. Disintegration and dissolution of tablets

Question 36

What are the functions of excipients?

Answer 36

i. To enhance stability e.g. antioxidants ii. Patient acceptability e.g. colourants, flavour iii. Aid in manufacturing e.g. binder, lubricants iv. Aid in product identification e.g. colourants v. To optimise drug release e.g. disintegrants

Question 37

What are excipients?

Answer 37

Pharmaceutical excipients are any substance other than the active drug product which is included in a drug formulation to either aid manufacture, identification, enhance stability, performance, or patient acceptability.

Question 38

What are diluents? Classify them with examples.

Answer 38

Diluents are excipients added to make the required bulk for tablet formulation. They are divided into: i. Organic materials: sugars, starches, cellulose. ii. Inorganic materials: Dicalcium phosphate dihydrate iii. Co-processed materials: Emdex®, Ludipress®.

Question 39

What are binders? Give 5 examples.

Answer 39

Binders are excipients added to tablet formulations to impart cohesiveness to powders. Examples: i. Sucrose ii. Liquid glucose iii. Acacia iv. Tragacanth v. Guar gum vi. Methylcellulose vi. Ethylcellulose

Question 40

What are disintegrants?

Answer 40

Disintegrants are agents added to tablet or capsule formulations to facilitate the breakup or disintegration of the tablet or capsule into smaller particles that dissolve more rapidly in the gastrointestinal fluids.

Question 41

What are the mechanisms of tablet disintegration?

Answer 41

i. Capillary action ii. Swelling iii. Heat of wetting iv. Particle repulsive force v. Deformation vi. Release of gases vii. Enzymatic function

Question 42

Give 3 examples of disintegrants.

Answer 42

1. Starch USP 2. Starch 1500 3. Carbon dioxide 4. Explotab®

Question 43

Give 3 examples of glidants.

Answer 43

1. Talc 2. Starch 3. Powdered cellulose

Question 44

Give 3 examples of lubricants.

Answer 44

A. Insoluble i. Talc ii. Waxes iii. Stearates B. Soluble i. Boric acid ii. Sodium benzoate iii. Sodium oleate iv. Sodium acetate

Question 45

Give 3 examples of antiadhesive/antisticking agents.

Answer 45

i. Talc ii. Corn starch iii. Stearates