Cancer chemotherapy often requires the untargeted delivery of large amounts of poorly soluble drugs. Block-copolymer nanoparticles are emerging as a viable vehicle for the transportation of chemotherapy drugs to their intended targets and as a means of increasing the solubility of the drugs, thus reducing the dosage that is necessary to fight tumors. We perform discontinuous molecular dynamics (DMD) simulations on systems containing block copolymers and drug molecules in order to understand how block copolymer nanoparticles assemble, what conditions encourage good encapsulation, and what mechanisms may be at work in the self-assembly of these nanoparticles. In this talk, we describe the effect of the presence of drug on the phase behavior of the block copolymer-solvent system. We also investigate the effect of system density, copolymer and drug mole fraction, and the interaction strength between components in the system to determine which of these variables has an effect on drug encapsulation. We also investigate the evolution of the density profile of the micelles over time in order to understand how these nanoparticles change during the course of their formation. We find that the presence of drug makes micelle formation easier. We also find that too little or too much attraction between hydrophobic head blocks can lead to poor encapsulation, while density and polymer/drug mole fraction seem to have little effect on drug encapsulation. Our investigation of the density profile of the micelles reveals that drugs migrate to the center of the nanoparticle after the nanoparticle has formed, creating a core of drug surrounded by copolymer. We propose that good encapsulation results from conditions that favor the association of drug and copolymer head block as opposed to the separate association of each hydrophobic component. Our results can be used by experimentalists as a framework for optimizing the drug encapsulation process by encouraging such interactions.