FUNCTIONALISED MESOPOROUS SILICA NANOPARTICLES AS DRUG CARRIER.

This study describes the amino-functionalization of the MCM-41 mesoporous matrix by post-synthesis grafting using 3-aminopropyltriethoxysilane (APTES) and the characterization of amino-functionalized mesoporous silica MCM-41 loaded with magnolol (MGN) in order to achieve modified drug delivery systems. The aminofunctionalization of silica MCM-41 with three different levels in the number of the amino groups introduced was carried out by grafting in a field of ultrasound. MCM-41 shows a one-dimensional system of the pores from cylindrical channels aligned hexagonally, diverging in three directions and interconnecting only within the same channel system. The major advantage of this material is its meso- and microporosity controllable by functionalization with organic groups and its ability to accommodate active molecules of different sizes. The powders obtained were characterized structurally by X-ray diffraction, texturally and morphologically by nitrogen adsorptiondesorption, and spectrophotometrically by IR spectrophotometry. Natural products are proved historically to be a promising pool for drug discovery and application that have reduced toxicity, less side effects and are significantly well tolerated by the human body. The fascinating multiple biological activities of magnolol (a neolignan polyphenolic compound isolated from the bark of Magnolia spp.) encourage researches on development of new approaches for delivery and administration so that to maximize its potential benefit. The results obtained showed that by grafting the amino groups in the silica MCM-41 we obtained amino-functionalized silica MCM-41 with an ordered structure, with specific surfaces and pore sizes that differ from the original matrix, which was reflected in the amount of MGN immobilized. The structure and pore architecture of the silicate materials have a key role in both the loading capacity of silica with MG and the rate of release of this drug substance. The efficient uptake of magnolol was also confirmed by BET measurements, which allowed the calculation of the textural properties of the synthesized materials by means of BET specific surface area, total pore volume and pore diameter. It was demonstrated that the process of aminofunctionalization of silica material leads to an enhanced MGN delivery system with a prolonged release profile fitted on a sigmoidal model. In vitro dissolution tests have been performed using a SR 8 Plus Series (AB & L Jasco) device, according to the experimental protocole. The quantitative determination of MG was performed by HPLC method at λ = 290 nm developed in-house. Results showed a 96.57% degree of retrieval and confirm the hypothesis that this method can be used for the quantitative determination of MGN loaded in silicate matrices as modified release formulations. [ABSTRACT FROM AUTHOR]