Figure 1.
The molecular structures of dexamethasone (a) and 2-hydroxypropyl-β-cyclodextrin (b). R = -H or –CH2CHOHCH3.
Figure 2.
Aqueous solubility of dexamethasone as a function of increasing HPβCD concentration at 25°C.
Data are presented as mean ± SD (error bars smaller than symbols); n = 3 in each experimental group.
Figure 3.
Dexamethasone flux across Caco-2 monolayers as the free drug (•) vs the drug-HPβCD complex (○), and the corresponding Papp values in centimeters per second (right panel).
Data are presented as mean ± SD; n = 4 in each experimental group.
Figure 4.
Papp values of dexamethasone across Caco-2 monolayers at different rotation speeds (0, 50, and 100 rpm).
Data are presented as mean ± SD; n = 4 in each experimental group.
Figure 5.
Effective permeability values (Peff, cm/sec; right panel) and outlet/inlet concentration ratio (C′out/C′in; left panel) of dexamethasone as the free drug (○) vs the drug-HPβCD complex (•), determined using the in situ single-pass rat jejunal perfusion model.
Data are presented as mean ± SD; n = 4 in each experimental group.
Figure 6.
Theoretical vs. experimental apparent permeability (Papp; cm/sec) of dexamethasone in the PAMPA model as a function of increasing HPβCD levels.
Experimental data presented as mean ± SD (error bars smaller than symbols); n = 4.
Figure 7.
The overall effects of increasing HPβCD levels on dexamethasone apparent solubility and permeability, based on the mass transport model employed in this work.