Dr Moks Lectures Flashcards
What is a solution
What is an ointment
What is a colloid
What does intra venous mean
What does topical mean
What does a surfactant do
Reduces surface tension
What is a micelle
How big is a colloidal system
<1 micrometres
Do colloids scatter Iight?
Yes, this is known as the Tyndall effect
What is the brown Ian motion?
Liquid molecules are always in motion, under a microscope you can observe that the larger colloidal particles are kept in suspension because of this constant bombardment
What is adsportion?
Molecules STICK to the surface of an adsorbent, chemical associated to surface of the agent
How would you separate a colloidal system?
By dialysis - use of a semi-permeable membrane with small enough pores to allow only the ions and the continuous phase to move through, leaving the colloids in the tube
How would you desperate charged colloidal particles?
With use of electrophoresis
What are the types of colloids (physically)
Gas in liquid or solid Liquid in gas, liquid or solid Solid in gas, liquid or solid
What are the types of colloids? (Ionically)
Lyophobic - solvent hating (e.g hydrophobic if continuous phase is H2O). Lyophilic - solvent liking (e.g hydrophilic if H2O)
What are foams?
Gases in liquids/solids
How do you reduce foam?
Using defoamers/ anti foaming agents. These act as small droplets which displace surfactants which stabilise thin films.
What are the three types of degradation of drugs
Chemical
Physical
Microbial
What are the four types of chemical degradation?
Hydrolysis
Oxidation
Photodegredation
Polymerisation
Dimerisation
How would you reduce hydrolysis of a drug?
Surfactants
Complexation
How would you circumvent auto-oxidation?
Exclude oxygen
Add antioxidants
How would you reduce photodegredation
Filter light with amber glass or coating for tablets
Store in dark areas