Raft-forming agents Flashcards
Gaviscon Double Action active ingredients
Sodium alginate
Calcium carbonate
Sodium bicarbonate
Solubility of alkali metal salts of alginates
Water-soluble
2 main types of glass used in pharmaceutical packaging
Neutral glass (Type 1) Soda-lime-silica glass (Type II or III)
Which glass packaging is used for peptac?
Soda-lime-silica glass Type III
Neutral glass (Type I)
Borosilicate glass containing significant amounts of boric oxide, aluminium oxide alkali and/or alkaline earth oxide
Soda-lime-silica glass (Type II or III)
Silica glass containing alkali metal oxides, sodium oxide & alkaline earth oxides (calcium oxide)
What is a chemical instability caused by glass packaging?
Alkali components may leach from glass
Use of Carbomer in Gaviscon Cool Liquid
Emulsifying agent, Polymeric suspending agent, viscosity-increasing material
- highest molecular weight
- crosslinked
Use of Parahydroxybenzoates in Gaviscon cool liquid
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
Why are parahydroxybenzoates preservatives less active at higher pH?
Phenolate ion is more likely to form
What increases antimicrobial activity?
Longer chain esters
Which parahydroxybenzoate derivative has a higher aqueous solubility?
Methyl is higher compared to Propyl + Butyl
Use of sodium saccharin
Sweetener
300-600x sweeter than sugar
Suitable for diabetics
What are the flavourings for Gaviscon Cool Liquid?
Mint flavour no.4 + no.5
Why are mint flavourings used?
For digestion + heartburn remedies
Why is peppermint oil used?
Relieve irritable bowel syndrome
Use of sodium hydroxide
pH modifier - adjust pH
Function of purified water
Vehicle
Difference between Peptac + Gaviscon
Gaviscon was an innovator product
Peptac is a generic equivalent
Use of Isopropyl alcohol in peptac liquid
Cosolvent - make formulation more lipophilic
Which raft-forming product contains peppermint oil
Peptac peppermint liquid
Which type of glass is gaviscon cool liquid supplied in?
Glass bottles - 2 year shelf life
What bottles have an 18 month + 12 month shelf life
18 month = HDPE (high density polyethylene)
12 month = PET (Polyethylene terephthalate)
Glass
non-reactive + impermeable
BP; appendix XIX B. Glass containers for pharmaceutical use
HDPE
Not permeable to vapours
Methyl parahydroxybenzoate for HDPE containers
PET
Less permeable to oxygen than HDPE
Paraben absorption has caused concerns
Why can’t peptac liquid be refrigenated or frozen?
Sodium alginate will cake
Why can’t peptac liquid be stored above 25 degrees?
Microbial growth
Preservative hydrolysis
More than 60 degrees causes alginate depolymerisation
Which packaging material is most susceptible to paraben absorption
Glass > HDPE > PET
PET is most susceptible
A ___ log P means a ____ aqueous solubility
lower
higher
