ABSTRACT
As more and more active pharmaceutical ingredients in drug
development are being classified as BCS II/IV due to poor aqueous
solubility,1 there have been significant challenges to successfully
formulate these sparingly soluble compounds. One approach to
make these drug substances more bioavailable is to dissolve them in
lipid based, or lipophilic, matrices. Because the drug substances are
typically pre-dissolved in the formulationmatrix, dissolution testing
is not conducted with the same focus on drug substance solubility.
As the drug substance solubility is not a strong test consideration,
the dissolution test may be more aptly referred to as a dispersion
test, meaning that the lipid-based formulation will be released in
aqueous dissolution medium and form an emulsion. In fact, there
are a few notable differences in dissolution testing of lipid-based
formulations versus more conventional formulations that will be
discussed in this chapter.
