Dissolution Kinetics of a BCS Class II Active Pharmaceutical Ingredient

Preparation of pH-Responsive Vesicular Deferasirox: Evidence from In Silico, In Vitro, and In Vivo Evaluations

pH-sensitive nanocarriers can effectively deliver anticancer drugs to tumors and reduce the adverse effects of conventional chemotherapy. In this light, we prepared a novel pH-responsive deferasirox (DFX)-loaded vesicle and comprehensively performed in silico, in vitro, and in vivo studies to examine the properties of the newly synthesized formulation. Physiochemical assessment of the developed formulations showed that they have an average size (107 ± 2 nm), negative zeta potential (-29.1 ± 1.5 mV), high encapsulation efficiency (84.2 ± 2.6%), and a pH-responsive release. Using the molecular dynamics simulation, the structural and dynamic properties of ergosterol-containing niosomes (ST60/Ergo) in the presence of DFX molecules were analyzed and showed a good interaction between DFX and vesicle components. Cytotoxic assessment showed that niosomal DFX exhibited a greater cytotoxic effect than free DFX in both human cancer cells (MCF-breast cancer and Hela cervical cancer) and induced evident morphological features of apoptotic cell death. No marked difference between the ability of free and niosomal DFX was found in activating caspase-3 in Hela cells. Eight weeks of intraperitoneal administrations of free DFX at three doses caused a significant increase in serum biochemical parameters and liver lipid peroxidation. Treatment with 5 mg/kg dose of niosomal DFX caused a significant increase in serum creatinine (P < 0.05); however, other parameters remained unchanged. On the other hand, administration of niosomal DFX at the highest dose (10 mg/kg) significantly increased serum creatinine (P < 0.05), BUN, and serum liver enzymes compared to the control rats (P < 0.001). Based on the results, the application of pH-responsive DFX-loaded niosomes, as a novel drug delivery platform, may yield promising results in cancer treatment.

Dissolution Kinetics of a BCS Class II Active Pharmaceutical Ingredient: Diffusion-Based Model Validation and Prediction

In this work, a diffusion-theory-based model has been devised to simulate dissolution kinetics of a poorly water-soluble drug, ibuprofen. The model was developed from the Noyes-Whitney equation in which the dissolution rate term is a function of the remaining particulate surface area and the concentration gradient across the boundary layer. Other dissolution parameters include initial particle size, diffusion coefficient, material density, and diffusion boundary layer thickness. It is useful for predicting nonsink circumstances under which pure API polydisperse powders are suspended in a well-mixing tank. The model was used to compare the accuracy of simulations using spherical (single dimensional characteristic length) and cylindrical particle (multidimensional characteristic lengths) geometries, with and without size-dependent diffusion layer thickness. Experimental data was fitted to the model to obtain the diffusion layer thickness as well as used for model validation and prediction. The CSDs of postdissolution were also predicted with this model, demonstrating good agreement between theory and experiment.