Stability and Excipients Flashcards
(30 cards)
Surfactant job
surface active agent that lowers the surface tension between two ingredients (ex: oil and water) making them more miscible
Surfactant mechanism of action
Amphiphilic micelle structure = forms droplets within the liquid
OR
amphiphilic film between the two surfaces
Emulsifiers
added to emulsion (2 liquids that don’t mix well) to help keep droplets dispered throughout the liquid
Suspending Agents
added to suspensions (a solid in a liquid) to keep the particles from settling
Levigating Agent
Used to grind down partibles in a liquid form
EX: glycerin and mineral oil
Polyethethylene glycol (PEG) use
Surfacant (Emulsifier)
Delivery vehicle (increases half life)
Lubricant
Polybase = suppository base
Hydrophilic-lipophilic balance (HLB)
> 10 = hydrophilic (HIGH) o/w
< 10 = lipophilic (LOW) w/o
Oxidation
When product loses electrons that is catalyzed by heat, light, and metals. Oxidation will produce free radicals.
most suspectible are structures with -OH (ex: epinephrine)
How to help prevent oxidation?
Light protection (amber glass)
Temperature control
Chelating agents
Antioxidants
Control pH
Hydrolysis
Water will cause cleavage of a bond on a molecule
most susceptible are structures with esters, amide, and lactams
EX: Aspirin
How do you prevent hydrolysis?
Dessicants to suck up/absorb moisture
Light protection
Chelating agents
Hygroscopic salt (water absorbing)
Prodrug formulations = active form will be created with hydrolysis
Photolysis
breakage of covalent bonds with light exposure
most susceptible: ascorbic acid, folic acid, nitroprusside, phytonadione
Excipient job
Any additive to a compounding product
EX: buffer, binder, diluents, lubricant, preservatives
Binders
help stick
EX; starch, sucrose, acacia
Diluents
make something more dilute when it comes to suspension
EX: water, glycerin, alcohol in liquid
Fillers
bulk up small amount
EX: lactulose, starches, cellulose, petrolatum, calcium salts
Disintegrants
fascillitates the dissolving of tablets after oral administration
EX: alginic acid, cellulose, polacrillin potassium, starches
Lubricants
prevent ingredients from sticking together
EX: magnesium stearate
Preservatives
prevent microorganism growth
DO NOT USE IN NEONATES
“benz”, “cetyl”, “parabens”, “phenyl”
EX: sodium benzoate, sorbic acid, EDTA
Buffers
maintain the pH
EX: acidic - hydrochloric acid, sodium acetate
basic - sodium hydroxide, boric acid
List the emollient in order from least water to most
Ointment (0 - 20% water)
Cream
Lotion
Gel
Aqueous solutions of poloxamers at room temp vs fridge?
Fridge - liquid formulation
Room temp - gel formulation
What are the 4 ointment groups?
- Hydrocarbon - NO WATER (Vaseline, white petrolatum
- Absorption - w/o
- Water-removeable - o/w more correctly called a cream
- Water-soluble - does not contain petrolatum, more correctly called gel
What solvent should be avoided in children?
Alcohol
