Preparation and characterization of octyl phenyl polyoxyethylene ether modified organo-montmorillonite for ibuprofen controlled release

To fabricate a hydrophobic pharmaceutical formulation with the use of montmorillonite (MMT), the strong polarity and structural properties of montmorillonite were modified by via simple and convenient wet ball-milling method using the nonionic surfactant , octyl phenyl polyoxyethylene ether , as the modifier, to improve the MMT's affinity to hydrophobic organic drug, ibuprofen . The resultant organo-montmorillonite (OPP-MMT) was characterized by the means of scanning electron microscopy, dynamic light scattering , Fourier transform infrared spectroscopy , X-ray diffraction, transmission electron microscopy , thermogravimetric analyzer, BET-specific surface area measurements, drug adsorption and in vitro release experiments, and in vitro cell viability assay . Experimental results showed that octyl phenyl polyoxyethylene ether was successfully inserted into the interlayer of the raw Na-MMT during the wet ball-milling process. The adsorption and intercalation modification of octyl phenyl polyoxyethylene ether destroyed the rigid structure of Na-MMT, enlarged the interlayer spacing of Na-MMT, and enhanced its specific surface area, pore volume and mean mesopore size, which made it be more conducive to the loading of hydrophobic organic drugs. The adsorption analysis of OPP-MMT on ibuprofen showed that the affinity of OPP-MMT to hydrophobic drugs was better than that of Na-MMT, which was beneficial to the loading of ibuprofen. Moreover, the good affinity of OPP-MMT to hydrophobic drug allowed it to exhibit good controlled release properties for the drug delivery.