Optimizing etodolac and quercetin loaded MSNs using taguchi design: an approach for enhancing drug loading efficiency

The application of mesoporous silica nanoparticles (MSN) as a drug carrier system got immense attention in the past few years due to their exceptional high drug loading efficiency. However, the process of drug loading is quite challenging compared to other lipid-based drug delivery systems. Hence, the MSNs using different catalysts were synthesized, and their mesoporous material characteristic was confirmed by the type IV adsorption-desorption isotherm using BET analyzer. The effect of solvent selection and other process parameters (drug to MSNs ratio, period of loading, and stirring speed) on the loading of BCS class II and IV model drugs etodolac(ETD) and quercetin(QUR) respectively were investigated with the help of Taguchi DOE. The predicted value for the highest % drug loading was close to the experimental value(19.04 ± 0.50 % and 11.40 ± 0.18 % for ETD and QUR respectively). It was interesting to note, that the solvent selection had the highest impact on the drug loading of ETD into the MSNs, whereas for QUR this parameter was insignificant. Hence reflecting that a generalized procedure for the drug loading into the MSNs cannot be followed and had to be critically studied. Also, the loading of ETD and QUR into the MSNs improved the aqueous solubility (3.08 and 2.5 folds respectively). Further the in-vitro drug release properties were evaluated for ETD and QUR from MSNs in various drug release mediums to explore their release mechanism from MSNs using in vitro drug release kinetic modelling.