Atomistic Description of the Solubilisation of Testosterone Propionate in a Sodium Dodecyl Sulfate Micelle

Large-scale molecular dynamics simulations were used to study the structural and dynamic properties of the solubilization process of testosterone propionate (TSTP) within sodium dodecyl sulfate (SDS) micelles. We observed that the TSTP spontaneously adsorb onto the SDS micelles and preferentially reside among the polar head groups of the SDS molecules. We found that the SDS micelle is slightly aspherical in size and has a surface area of ∼170 Å(2)/molecule, while the SDS+TSTP micelle is more aspherical and has a surface area of ∼156 Å(2)/molecule. The structural properties of the interior of the SDS micelle and the hydration of the SDS headgroup are largely undisturbed by the presence of the TSTP. However, there seems to be a correlation between the location of the TSTP molecules and the location of Na(+) counterions on the surface of the SDS micelle. Additionally, we also observe that the TSTP molecules diffuse on the surface of the SDS micelle and try to organize themselves such that they are approximately equidistant from one another.