Physicochemical characterization, released profile, and antinociceptive activity of diphenhydraminium ibuprofenate supported on mesoporous silica.

The thermal, physical, and morphological properties of diphenhydraminium ibuprofenate ([DIP][IBU]) adsorbed onto mesoporous silica (SiO2-60 Šand SiO2-90 Å) from solution were determined. The thermal, physical, and morphological properties of [DIP][IBU] supported on silica were determined. The adsorption of [DIP][IBU] on the pores and surface of silica was proven by N2 adsorption/desorption isotherms. Additionally, release profiles were determined for all systems, and the antinociceptive activity of neat [DIP][IBU] and [DIP][IBU] supported on silica were determined. The interaction of [DIP][IBU] and silica was dependent on pore size, with the formation of a [DIP][IBU] monolayer on SiO2-60 and a multilayer on SiO2-90. The release profile was sustained and slow and dependent on the pore size of the silica, in which the smaller the pore size, the faster the release. The nociceptive evaluation showed that [DIP][IBU] presents a greater (99.21 ±â€¯0.85%) antinociceptive effect than the ibuprofen (46 ±â€¯4.3%). Additionally, [DIP][IBU] on SiO2-60 (90 ±â€¯5.8%) had a greater antinociceptive effect than on SiO2-90 (73 ±â€¯13.2%), which indicates that in vivo tests are in accordance with the in vitro experiments.