An Alcohol-Free SiO₂ Sol-Gel Matrix Functionalized with Acetic Acid as Drug Reservoir for the Controlled Release of Pentoxifylline

Figure 5

Transmission electron microscopy images of acetic acid-SiO₂ (a), (b) and PTX-acetic acid-SiO₂ (c), (d).

(a)

(b)

(c)

(d)