Mesoporous Silica for Drug Delivery: A Quantum Mechanical Simulation
The mechanisms of interaction between solid excipients and drugs are based on surface chemistry related phenomena. Consequently, understanding the physico-chemical features of surfaces is a fundamental step to describe and predict the strength of these interactions. The results of this analysis can shed light on how the nature of the excipient can affect the properties of a drug formulation. Among silica-based mesoporous materials, MCM-41 (Mobil Composition of Matter) is one of the most studied. In 2001 it was first proposed as a drug delivery system, with ibuprofen as a model drug. In this project, this drug molecule was studied in interaction with an accurate model of MCM-41, providing structures and interaction energies for the adsorption of ibuprofen with this material of unprecedented quality. Simulation of a variety of physical observables (infrared and NMR spectra) represents a key point in order to validate the results by comparison with experimental data.
Why was HPC required?
The chemical systems that were investigated in this project are made up of almost one thousand atoms in the form of a crystalline material. To study such systems with the state-of-the-art methods chosen for this project (ab initio DFT calculations, using hybrid functionals and accounting for London interactions) High Performance Computing (HPC) is the method of choice. The simulations, which were made possible through the European HPC initiative PRACE (Partnership for Advanced Computing in Europe) were completed in a feasible time only by exploiting the thousands of processors available on HPC system SuperMUC of Leibniz Supercomputing Centre. B3LYP-D2 calculations have been run using the massive parallel version of CRYSTAL09 code whereas AIMD calculation at PBE-D2 using the CP2K code.
Benefit from the insight gained.
Thanks to HPC, the atomistic details provided by these accurate calculations would allow, for the first time, to understand the interaction energy of ibuprofen (as a model drug) with a mesoporous silica material. This study will also try to give a molecular insight into the physical state of ibuprofen confined in a porous medium, a key point to understand its release in the body. The authors believe that the results, in particular the calculated interaction energies, may be useful to design new functionalized MCM-41 materials apt to modulate the strength of interaction with ibuprofen and similar drugs.
Prof. Piero Ugliengo (PI), Massimo Delle Piane (PhD student), DR. Marta Corno (PostDoc)
Theoretical Chemistry Group – University of Torino, Department of Chemistry
Via Giuria 7, I-10125 Torino (Italy)