66. Sanganwar, Ganesh P.; Gupta, Ram B.. Dissolution-rate enhancement of fenofibrate by adsorption onto silica using supercritical carbon dioxide. International Journal of Pharmaceutics (2008), 360(1-2), 213-218.
Dissoln. rate of a poorly water-sol. drug, fenofibrate, is increased by adsorbing the drug onto silica. The adsorption is achieved by first dissolving the drug in supercrit. carbon dioxide and then depressurizing the soln. onto silica. Loadings of up to 27.5 wt.% drug onto silica are obtained. Since solvents are not used in the loading process, the fenofibrate/silica formulation is free of any residual solvent, and carbon dioxide is freely removed upon depressurization. The formulation is characterized using IR spectroscopy, UV spectroscopy, X-ray diffraction, differential scanning calorimetry and SEM. Based on in vitro dissoln. study, a significant increase in the dissoln. rate (.apprx.80% drug release in 20 min) of drug-silica formulation is obsd. as compared to micronized fenofibrate (.apprx.20% drug release in 20 min), which can be attributed to increase in the surface area and decrease in the crystallinity of drug after adsorption onto silica. Two different formulations are compared: (A) amorphous fenofibrate/silica and (B) slightly cryst. fenofibrate/silica. The second formulation is found to be more stable on storage.