L49- liquid dosage forms- emulsions and suspensions

what are some formulation considerations when considering the physical properties

• particle size: increasing the stability by modifying the particle sedimentation

it should be minimised by chemical methods or physical methods

• wetting properties of drug

insoluble drug particles: hydrophobic, not easily wetted

surface- active agents which decrease interfacial tension

particles poorly wetted: aggregation

describe crystal growth in suspensions + how can it be controlled

• in a suspension small particles have a higher dissolution rate than the larger ones

• when there’s a change in storage temperature there may be crystallisation on the surface of the larger particles

• hydrophilic polymers decrease crystal growth through adsorption on to suspended drug particles ( protection )

• things such as temperature cycling and monitoring the particle diameter and physical stability can help control it

what are the usual components of oral suspensions

what are the two methods of manufacturing suspensions

• direct incorporation

• precipitation method

what is the direct incorporation method of making suspension + what need to be controlled in this methods

• this is when all components are added to the vehicle e.g. pure water ups

• the mixing rate needs to be controlled:

• the particle size

what is the precipitation method for making suspensions + potential problems

what is an emulsion

its a disperse systems in which an insoluble liquid is dispersed into a second liquid phase

disperse phase= phase that’s sub-divided

continuous phase= phase in hwich disperse phase is distributed

what are some of the uses of emulsions

what are the advantages of

what are the disadvantages of emulsions

what are the 3 main types of emulsions that we can have

what are some basic factors that are needed in an emulsion/cream

what defines the type of emulsion that’s manufactured

the stability of its droplet phase

how do you test for different emulsion types

what are the 4 types of emulsion instability