Lipid-Based Drug Delivery Systems

Table 3

Pouton’s classification of lipid-based delivery systems.

	Type I	Type II	Type IIIA	Type IIIB
% triglycerides or mixed glycerides	100	40–80	40–80	<20
% surfactants	—	20–60 (HLB < 12)	20–40 (HLB > 11)	20–50 (HLB > 11)
% hydrophilic cosolvents	—	—	0–40	20–50
Particle size of dispersion (nm)	Coarse	100–250	100–250	50–100
Significance of aqueous dilution	Limited importance	Solvent capacity unaffected	Some loss of solvent capacity	Significant phase changes and potential loss of solvent capacity
Significance of digestibility	Crucial requirement	Not crucial, but likely to occur	Not crucial, but may be inhibited	Not required and not likely to occur