Raft-forming agents

Question 1

Gaviscon Double Action active ingredients

Answer 1

Sodium alginate
Calcium carbonate
Sodium bicarbonate

Question 2

Solubility of alkali metal salts of alginates

Answer 2

Water-soluble

Question 3

2 main types of glass used in pharmaceutical packaging

Answer 3

Neutral glass (Type 1) 
Soda-lime-silica glass (Type II or III)

Question 4

Which glass packaging is used for peptac?

Answer 4

Soda-lime-silica glass Type III

Question 5

Neutral glass (Type I)

Answer 5

Borosilicate glass containing significant amounts of boric oxide, aluminium oxide alkali and/or alkaline earth oxide

Question 6

Soda-lime-silica glass (Type II or III)

Answer 6

Silica glass containing alkali metal oxides, sodium oxide & alkaline earth oxides (calcium oxide)

Question 7

What is a chemical instability caused by glass packaging?

Answer 7

Alkali components may leach from glass

Question 8

Use of Carbomer in Gaviscon Cool Liquid

Answer 8

Emulsifying agent, Polymeric suspending agent, viscosity-increasing material

• highest molecular weight
• crosslinked

Question 9

Use of Parahydroxybenzoates in Gaviscon cool liquid

Answer 9

Antimicrobial preservatives - mixture of different parabens

• less active @ higher pH when phenolate ion can form
• methyl has higher aqueous solubility that propyl + butyl
• longer chain ester have higher antimicrobial activity

Question 10

Why are parahydroxybenzoates preservatives less active at higher pH?

Answer 10

Phenolate ion is more likely to form

Question 11

What increases antimicrobial activity?

Answer 11

Longer chain esters

Question 12

Which parahydroxybenzoate derivative has a higher aqueous solubility?

Answer 12

Methyl is higher compared to Propyl + Butyl

Question 13

Use of sodium saccharin

Answer 13

Sweetener
300-600x sweeter than sugar
Suitable for diabetics

Question 14

What are the flavourings for Gaviscon Cool Liquid?

Answer 14

Mint flavour no.4 + no.5

Question 15

Why are mint flavourings used?

Answer 15

For digestion + heartburn remedies

Question 16

Why is peppermint oil used?

Answer 16

Relieve irritable bowel syndrome

Question 17

Use of sodium hydroxide

Answer 17

pH modifier - adjust pH

Question 18

Function of purified water

Answer 18

Vehicle

Question 19

Difference between Peptac + Gaviscon

Answer 19

Gaviscon was an innovator product

Peptac is a generic equivalent

Question 20

Use of Isopropyl alcohol in peptac liquid

Answer 20

Cosolvent - make formulation more lipophilic

Question 21

Which raft-forming product contains peppermint oil

Answer 21

Peptac peppermint liquid

Question 22

Which type of glass is gaviscon cool liquid supplied in?

Answer 22

Glass bottles - 2 year shelf life

Question 23

What bottles have an 18 month + 12 month shelf life

Answer 23

18 month = HDPE (high density polyethylene)

12 month = PET (Polyethylene terephthalate)

Question 24

Glass

Answer 24

non-reactive + impermeable

BP; appendix XIX B. Glass containers for pharmaceutical use

Question 25

HDPE

Answer 25

Not permeable to vapours

Methyl parahydroxybenzoate for HDPE containers

Question 26

PET

Answer 26

Less permeable to oxygen than HDPE

Paraben absorption has caused concerns

Question 27

Why can’t peptac liquid be refrigenated or frozen?

Answer 27

Sodium alginate will cake

Question 28

Why can’t peptac liquid be stored above 25 degrees?

Answer 28

Microbial growth
Preservative hydrolysis
More than 60 degrees causes alginate depolymerisation

Question 29

Which packaging material is most susceptible to paraben absorption

Answer 29

Glass > HDPE > PET

PET is most susceptible

Question 30

A ___ log P means a ____ aqueous solubility

Answer 30

lower

higher