  A key step in the development of a new drug is the design of drug-excipient
complexes that lead to an optimal drug release kinetics. Computational
chemistry, specifically enhanced sampling molecular dynamics methods, can play
a key role in this context by minimizing the need for expensive experiments and
reducing cost and time. Here, we show that recent advances in enhanced sampling
methodologies can be brought to fruition in this area. We demonstrate the
potential of these methodologies by simulating the release kinetics of the
complex praziquantel-montmorillonite in water. Praziquantel finds promising
applications in the treatment of schistosomiasis, but its biopharmaceutical
profile needs to be improved and a cheap material like the montmorillonite clay
would be a very convenient excipient. We simulate the drug release both from
surface and interlayer space and find that the time it takes to the drug to
diffuse from the interlayer space to the solution controls the release time.
