Excipients In Liquid Dosage Forms

Question 1

What are types of excipients in liquid dosage forms?

Answer 1

Solvents
Preservatives
Stabilizers/ anti-oxidant
Buffers
Isotonicity modifiers
Sweeteners
Flavors
Colors

Question 2

What are the types of solvents?

Answer 2

Water
Ethyl alcohol
Glycerol

Question 3

What are the advantages of water?

Answer 3

Cheap
Tasteless, odorless and colorless
Inert
Neutral
Physiologically compatible
Lack of toxicity
Available
Compatible with so many liquids
Can dissolve many drugs

Question 4

What are disadvantages of water?

Answer 4

Support growth of microorganisms when contaminated
Favorable medium for many chemical reaction
A medium for all the degradation processes
May contain minerals
Dissolve sugars, proteins → encourage growth of microorganisms

Question 5

What are the types of water?

Answer 5

Tap water (potable water)
Purified water
Water for injection
Bacteriostatic water for injection

Question 6

What is tap water?

Answer 6

It contains minerals and microorganisms
Not permitted to be used for liquid dosage forms for dispensing of pharmaceutical dosage forms
Used in the preparation of purified water

Question 7

Why tap water is not permitted to be used for liquid dosage forms for dispensing of pharmaceutical dosage forms?

Answer 7

Due to its possible bacterial contamination and the presence of dissolved salts that destroy the active ingredients or enhance their decomposition

Question 8

What is the microbiological specification of tap water?

Answer 8

Contains not more than 500 cfu/ml
Absence of individual pathogenic microorganisms, escherichia coli, salmonella, staphylococcus aureus and pseudomonas aeruginosa per 100 ml

Question 9

What is purified water?

Answer 9

Water free from minerals total solids < 10ppm
Prepared by distillation or ion exchange resins
Containers, closures and machine parts may be washed with portable water followed by suitably filtered purified water
Stored in stainless steel tanks or plastic tanks

Question 10

What is the microbiological specification for purified water?

Answer 10

Contains not more than 100 cfu per ml and indicates absence of pathogenic microorganisms

Question 11

What is water for injection?

Answer 11

Prepared from portable/purified water
Free from bacteria
Free from pyrogen
Free from minerals < 10ppm
Used for sterile products
WFI is sterile water may be found in containers of one liter

Question 12

What is microbiological specification for water for injection ?

Answer 12

Contains not more than 10 cfu per 100 ml
Shall have an endotoxin level of not more than 0.25 eu/mi

Question 13

What is bacteriostatic water for injection?

Answer 13

All characters of water for injection
Contains a bacteriostatic at specific concentration
Used for vials or multiple dose products
Volume must not exceed 30ml

Question 14

What are advantages of ethyl alcohol

Answer 14

Kills microbes
Used to extract alkaloid and glycosides
More specific for dissolving materials

Question 15

What are disadvantages of ethyl alcohol?

Answer 15

Volatile
Affects CNS, liver, git
Dissolves resins
Restricted use

Question 16

What are advantages of glycerol?

Answer 16

Not volatile
Not toxic
Antimicrobial activity
Viscosity is high
Effect is better because duration is more

Question 17

What are disadvantages of glycerol?

Answer 17

Hygroscopic
Dissolves gums, albumins, and tannins

Question 18

What is the definition of preservatives?

Answer 18

Agents used to prevent the growth of microbes found into or allowed to inter in the container

Question 19

What are examples of preservatives?

Answer 19

Benzoic acid 0.1 - 0.2%
Sodium benzoate 0.1 - 0.2%
Methyl parabens and propyl parabens 0.1 - 0.2%
Phenyl mercuric nitrate 0.002 - 0.01%

Question 20

What are characteristics of preservatives?

Answer 20

Antimicrobial agents
Toxic
Required for multiple dose administration

Question 21

What are properties of preservatives?

Answer 21

Must be used in the effective concentration
Must be safe, soluble and stable
Doesn’t interact with container or cover
Doesn’t interact with the drug or other ingredients in the formulation

Question 22

What are the factors enhancing degradation?

Answer 22

Light
Heat
Catalyst

Question 23

Drugs degradation occurs due to what?

Answer 23

Oxidation
Hydrolysis
Photo-degradation

Question 24

What are the methods used to control oxidation?

Answer 24

Use dry powder
Avoid direct exposure to air
Use antioxidant (ascorbic acid and chelating agent)

Question 25

What are the methods used to control hydrolysis?

Answer 25

Use dry powder followed by reconstitution just before use Use solvents as glycerin, propylene glycol Formulate at optimal pH at which least degradation occurs Store at not more than 25°C

Question 26

What are the methods used to avoid light?

Answer 26

Amber glass bottles An opaque secondary package may also be used for this purpose Storage in dark place

Question 27

What are tonicity adjusting agents?

Answer 27

Substances that are added to adjust the tonicity of the solution dosage forms and make them isotonic solutions

Question 28

Tonicity adjusting agents are added to what?

Answer 28

Ophthalmic preparations and parental dosage forms

Question 29

Hypotonic and hypertonic solutions may cause what to the patient?

Answer 29

Harm and pain

Question 30

What is the equation relating to the osmotic pressure of a solution to its concentration?

Answer 30

Question 31

What is isotonic solution?

Answer 31

Solutions of the same osmotic pressure as the biological fluids

Question 32

What is hypotonic solution?

Answer 32

Solutions that are more dilute

Question 33

What is hypertonic solution?

Answer 33

Solutions that are more concentrated

Question 34

What does the healthy body do In terms of isotonicity?

Answer 34

Maintains a delicate balance of water and electrolytes that are highly regulated by osmotic pressure and ion concentration

Question 35

What are the units used for ionic concentration?

Answer 35

mEq/L

Question 36

What are examples of tonicity adjusting agents?

Answer 36

Dextrose Glycerin Mannitol Potassium chloride Sodium chloride

Question 37

The tonicity of parenteral fluids may be adjusted with what?

Answer 37

Sodium chloride or glucose (dextrose)

Question 38

What is the usual range of sodium chloride and dextrose

Answer 38

Sodium chloride → 0,45 to 0.9% Dextrose → 5-10 %

Question 39

What are sweetening agents?

Answer 39

Provide sweetness and viscosity

Question 40

What is the natural sweetener?

Answer 40

Sugar → sucrose

Question 41

What concentration of sucrose does the syrup contain?

Answer 41

60 - 80 %

Question 42

High concentration of sugar does what to microorganisms?

Answer 42

Inhibits the growth

Question 43

When subjected to heat what happens to sucrose?

Answer 43

Hydrolyzed to glucose and fructose (invert sugar)

Question 44

What is the difference between sucrose and invert sugar?

Answer 44

Invert sugar is sweeter

Question 45

What is a disadvantage of natural sweeteners?

Answer 45

Can not be taken for diabetes and obesity

Question 46

What are examples of other sweeteners?

Answer 46

Sorbitol Glycerol Propylene glycol Methylcellulose (MC) hydroxyl ethyl cellulose (hc) Synthetic sweeteners such as saccharine, sucralose, aspartame

Question 47

What are the properties of MC and HC?

Answer 47

Not metabolized Non-caloric Viscosity enhancing agent Provide syrup-like consistency to vehicles for medicine intended for diabetes and those on restricted diets

Question 48

What are the properties of saccharin?

Answer 48

Synthetic 500 more sweeter than sucrose

Question 49

What are properties of aspartame?

Answer 49

Artificial sweeting agent Composed of 2 molecules, of aspartic acid Decomposes in the presence of water (used in solid form only)

Question 50

A flavoring agent is an excipient used to overcome what?

Answer 50

Question 51

What are the properties of flavoring agents?

Answer 51

They are either soluble or insoluble in water Flavors could be synthetic or naturally occurring agents

Question 52

What are examples of flavoring agents?

Answer 52

Question 53

What are aromatic waters?

Answer 53

They are saturated aqueous solutions of volatile oil substances and are used as solvents and flavoring agents

Question 54

What are examples of aromatic waters?

Answer 54

Rose water Caraway water Cinnamon water

Question 55

What are coloring agents used for?

Answer 55

Psychological, or identification purposes

Question 56

What colors are used?

Answer 56

The ones approved by FDA

Question 57

Why is tartrazine not used?

Answer 57

Due to allergy

Question 58

Natural or synthetic are preferred?

Answer 58

Natural

Question 59

What is a property that the colors should have?

Answer 59

Stability