PHARM124 Lecture 2: Pharm 124 – Study Notes Pt.2
Document Summary
A pharmaceutical suspension is defined as a coarse suspension containing finely divided insoluble material suspended in a liquid medium. Particle size is a useful way to categorize dispersions: less than 1 micron is a colloid, above 1 micron is a suspension. If we want to improve the stability of a suspension e would want to work with smaller particles. 1-50 micro meters is a fine dispersion. 50-100 micro meters is a coarse dispersion. With large particle size we expect a lot more stability problems. A suspension is always defined as a solid distributed in a liquid. This is a 2 phased system : dispersed phase also known as discontinuous phase or internal phase (insoluble, dispersion medium also known as external or continuous phase (liquid or semisolid) Important criteria is that the dispersed phase has to be insoluble in the medium it is dispersed in, if it was soluble we would have a solution.