gammaCD/HPgammaCD: synergistic solubilization.
The natural gamma-cyclodextrin (gammaCD) is like linear water-soluble dextrins, and unlike the natural alpha- and beta-cyclodextrins (alphaCD and betaCD), digested by salivary and pancreatic amylase. This gives gammaCD a very favorable toxicological profile. However, its usage is hampered by its relatively low solubilizing effect and tendency to form turbid solutions. Addition of 2-hydroxypropyl-gamma-cyclodextrin (HPgammaCD) to aqueous gammaCD solutions increases the complexation efficiency of gammaCD and reduces the turbidity. For example, 80:20 mixture of gammaCD and HPgammaCD is up to 50% more effective solubilizer for dexamethasone and hydrocortisone than expected based on the solubilizing effects of the individual cyclodextrins. Mixing alphaCD or betaCD with their more water-soluble derivatives only resulted in additive effects. Mixing gammaCD with HPgammaCD resulted in synergistic effect.
Jansook
Phatsawee
P
Faculty of Pharmaceutical Sciences, University of Iceland, Reykjavik, Iceland.
Loftsson
Thorsteinn
T
D002626:Chemistry, Pharmaceutical; D003907:Dexamethasone / Q000737:chemistry; D006854:Hydrocortisone / Q000737:chemistry; D008956:Models, Chemical; D009391:Nephelometry and Turbidimetry; D012995:Solubility; D047408:gamma-Cyclodextrins / Q000737:chemistry*
D047408:gamma-Cyclodextrins; C479659:hydroxypropyl-gamma-cyclodextrin; D003907:Dexamethasone; D006854:Hydrocortisone