D3 — Polymers & Oral Liquid Dosage Forms

What is a macromolecule?

Molecule composed of many atoms

What is a polymer?

High molecular weight substance of repeating monomers

What is PDMS?

Polydimethylsiloxane linear homopolymer

What is simeticone?

Activated dimeticone with silica

What is simeticone used for?

Defoaming agent for trapped wind

How does simeticone work?

Lowers surface tension of gas bubbles

What is the polymerisation range of simeticone?

n between 20 and 400

What are raft forming agents used for?

Preventing reflux in heartburn

How were alginate formulations discovered?

Serendipitously during contrast trials

What triggers alginate gel formation?

pH below 3.5

How does the raft float?

CO2 trapped in gel

What is the function of sodium alginate?

Soluble polymer forming gel in acid

What is the function of bicarbonate?

Produces CO2 for raft buoyancy

What does carbomer do?

Increases viscosity and stabilises suspension

What are parabens used for?

Antimicrobial preservatives

Why use multiple parabens?

Enhanced antimicrobial activity

Why is sodium saccharin used?

Sweetener suitable for diabetics

What drawback does saccharin have?

Metallic aftertaste in some people

Why are mint flavours used?

Traditional use in indigestion remedies

Why is sodium hydroxide included?

Adjusts pH to optimise viscosity

Why must pH not exceed 8 for parabens?

Risk of ester hydrolysis

Do Peptac and Gaviscon have the same actives?

Yes identical actives

Why do excipients differ?

Different formulation strategies

Why does Peptac contain isopropyl alcohol?

Cosolvent for peppermint oil

Why use ethyl and butyl parabens?

Increased lipophilicity

Why does Gaviscon use glass bottles?

Non reactive impermeable

Why do HDPE bottles have shorter shelf life?

Vapour permeability paraben absorption

Why do PET bottles have the shortest shelf life?

Higher paraben absorption risk

What happens if alginate products freeze?

Caking

What happens above 60°C?

Alginate depolymerisation