Solid lipid nanoparticles as carriers of hydrocortisone and progesterone complexes with beta-cyclodextrins

Inclusion complexes of hydrocortisone and progesterone were formed with beta-cyclodextrin or 2-hydroxypropyl-beta-cyclodextrin. The formation of the complexes was confirmed by differential scanning calorimetry (DSC). The inclusion complexes were incorporated in two types of solid lipid nanoparticles (SLN). In the presence of the complexes the sizes of SLN remained below 100 nm. DSC analysis showed that hydrocortisone and progesterone are dispersed in SLN in an amorphous state. Using the beta-cyclodextrin complexes the incorporation of the more hydrophilic drug, hydrocortisone, was higher than that of progesterone. Release of hydrocortisone and progesterone from SLN was lower when they were incorporated as inclusion complexes than as free molecules.