Mesoporous SBA-15 HPLC evaluation for controlled gentamicin drug delivery

Inclusion of prednicarbate in the SBA-15 silica

“…These results associated with the observed shift of the nitrogen isotherm after loading (Fig. 4), originated by the reduction in total nitrogen amount adsorbed under different relative pressure values [6], confirm that the drug was introduced inside the channels of the SBA-15, validating the prednicarbate encapsulation [8,20].…”

“…The release rate was also lower during the course of the experiment, demonstrating a modified release of prednicarbate when loaded in the SBA-15 [6,19,20]. The release rate of drug-loaded in the first 6 h was approximately fourfold higher than the rate from 6 to 24 h. This pronounced difference in the rates, representing around 78 % of the total drug released in the first 6 h, is attributed to easy dissolution and diffusion of the drug packed inside the pores and not adsorbed on the inner surface of them [5,6]. The large pore sizes of the SBA-15 (10 nm) might reduce steric diffusion resistance, contributing also to this faster release rate at the beginning of the experiment [20].…”

“…Figure 4 shows the N 2 adsorption/desorption isotherms and pore size distribution of silica type SBA-15 and the sample obtained through the loading process (pred/SBA-15). These materials exhibit IUPAC type IV isotherm with apparent hysteresis loop between 0.6 and 0.8 of relative pressure (p/p 0 ), indicative of a narrow distribution of mesoporous in the frameworks and characteristic of a SBA-15 of good quality [6,29,50,51]. The specific surface area was evaluated using BET method (S BET ).…”

“…Mesoporous silica matrices have been studied for this purpose due to their specific characteristics: pore size (2-50 nm) and its architecture; extensive surface area (400-1500 m 2 g -1 ) and pore volume (up to 2.2 cm 3 g -1 ) [1,2]; ability to undergo silanol functionalization, yielding to a modified host-guest chemical interaction during adsorption process, as well as the capacity to better control the drug diffusion profile, a highly desirable characteristic for drug delivery systems [1,[3][4][5][6][7][8][9][10][11][12][13][14]. Previous studies have evaluated the modified release of a large variety of poorly water-soluble substances, demonstrating the successful use of SBA-15 as a carrier material, which is characterized by high surface area, adequate pore volumes, narrow pore size distribution, and non-toxic nature [6,[15][16][17][18][19]. Furthermore, the loading of drugs in mesoporous silica can have a protective effect on the molecule, resulting in the improvement of its chemical stability, as observed by Qu and co-workers using thermogravimetry to evaluate captopril encapsulated in MCM-41 [20].…”

Periodic 3D nanoporous silica modified by amine or SPION nanoparticles as NSAID delivery system

“…The tuneable mesopore structure and modifiable surface of mesoporous silica nanoparticle allow incorporation of various classes of drug molecules. Pioneering work in use of periodic nanoporous silica nanoparticles for drug delivery was done by M. Valet Regí et al They studied the use of MCM-41 silica for controlled release of ibuprofen and the influence of surface morphology and its modification by amines to the release of the drug [14][15][16][17][18][19][20]. These works started intensive research and different drugs including antibiotics [21], drugs regulating blood circulatory disorders in the brain [22], antihypertensive drugs [23], anticancer drugs [24], antiviral drugs [25], vitamins [26], chemopreventive agents [27], antibacterial agents [28][29][30], non-steroidal anti-inflammatory drugs [31,32] were studied.…”