Ordered mesoporous carbons for ibuprofen drug loading and release behavior

Ibuprofen (IBU) was selected as model drug and loaded onto ordered mesoporous carbons (OMCs). Effect of the OMCs structures on IBU drug loading and release was studied for the first time. The carbon materials before and after IBU loading were characterized by N2 sorption analysis, small angle X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that the loading of IBU had not greatly changed the basic ordered pore structure of the OMCs. The IBU adsorption process followed the Langmuir adsorption and the adsorbed IBU amount was mainly a function of the specific surface area and pore volume. The two-step release process of a first fast release and then a slower release was observed. The release behavior of IBU was well correlated with time using a simple hyperbolic equation. The pore size was a crucial factor for the release rate of IBU, which increased with the increase of pore size.

The above figure showed the IBU release profile for the four drug loaded carbon samples. They exhibited a similar delivery profile. First, a fast release and then a slower release were observed. In fact, a simple hyperbolic equation could be fitted to these data with a correlation coefficient of 0.999.f=kit/(1+at)f=kit/(1+at)In this equation, f was the fractional release of drug, t was time, ki and a were adjustable parameters and could be obtained by least-squares analysis. The parameter ki with the slope of the release curve at t = 0 was the initial release rate. The ki values of C-70, C-70∗, C-100, and C-100∗ were 2.36, 1.77, 1.41, and 0.58, respectively. It was interesting that the increase of ki values was in accordance with the increase of pore sizes.Figure optionsDownload as PowerPoint slideResearch highlights
► Effect of the OMCs structures on IBU drug loading and release was studied for the first time.
► The loading of IBU had not greatly changed the basic ordered pore structure of the OMCs.
► A simple hyperbolic equation was obtained.