[1] Univ Kentucky, Dept Pharmaceut Sci, Lexington, KY 40506 USA
[2] Univ Kentucky, Electron Microscopy Ctr, Lexington, KY 40506 USA
[3] Univ Kentucky, Dept Chem Engn & Mat Sci, Lexington, KY 40506 USA
[4] Purdue Univ, Coll Pharm, Dept Ind & Phys Pharm, W Lafayette, IN 47907 USA