## 2 Material and Methods
### Methods  
Carboxylated multiwall carbon nanotubes were synthesized following a methodology published previously in [51]. CNTs were reacted with a mixture of concentrated sulfuric acid and nitric acid at 140 \({}^{\circ}\)C for 5, 10, and 40 minutes, respectively, in a microwave reactor (model: CEM Mars). This led to the formation of various amounts of carboxylic groups on the CNTs surface that had different hydrophilicity [28]. The carboxylated CNTs were filtered through a 10 um polytetrafluoroethylene (PTFE) membrane filter, washed to a neutral pH, and dried under vacuum at 65 \({}^{\circ}\)C.  
Drug/CNT composites were prepared by anti-solvent precipitation at room temperature. GF or SMZ (Figure 1) was saturatively dissolved in acetone. An antisolvent was prepared by dispersing f-CNTs in water under sonication for 10 min. The antisolvent was added dropwise into the drug solution under sonication and the solution turned cloudy immediately after the addition of the f-CNT suspension, which indicated crystal formation of the f-CNT/drug composites (which are referred to as GF-CNT\({}_{X}\) and SMZ-CNT\({}_{X}\), respectively, where x represents the carbon to oxygen ratio). The resulting solution was filtered through a 10 um PTFE membrane filter, washed, and dried in a vacuum oven until a constant weight was maintained.  
The resulting drug/CNT composites were characterized with a scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), an X-Ray diffractometer (XRD), thermogravimetric analysis (TGA), and elemental analysis. The dissolution was tested by dissolution testing apparatus 2. SEM and EDX was performed with a LEO 1530 VP (LEO Electron Microscopy Inc., Thornwood, NY, USA) and JEOL JSM-7900F (JEOL Ltd., Tokyo, Japan). TEM was performed with a Hitachi H-7500 Tungsten/LaB6 (Hitachi, Ltd., Tokyo, Japan) with a 100 KV energy bean. TGA was performed with a Perkin Elmer Pyris 1 thermogravimetric analyzer (PerkinElmer Inc., Waltham, MA, USA) which heated the samples from 30 \({}^{\circ}\)C to 1200 \({}^{\circ}\)C at 10 \({}^{\circ}\)C/min in air. Elemental analysis was performed using a Perkin-Elmer 2400 Series II elemental analyzer (PerkinElmer Inc., Waltham, MA, USA). Raman spectroscopy was performed with a Thermo Scientific DXR Raman Microscope (Thermo Fisher Scientific Inc., Waltham, MA, USA) with a 532 nm filter. Melting points were measured with a Perkin Elmer DSC 6000 (PerkinElmer Inc., Waltham, MA, USA). DSC was carried out under nitrogen; GF-CNT\({}_{X}\) samples were heated from 30 \({}^{\circ}\)C to 250 \({}^{\circ}\)C at 20 \({}^{\circ}\)C /min while SMZ-CNT\({}_{X}\) samples were heated from 30 \({}^{\circ}\)C to 200 \({}^{\circ}\)C at 20 \({}^{\circ}\)C /min. XRD was performed with a PANalytical EMPYREAN XRD (Malvern Panalytical Inc., Westborough, MA, USA) with a Cu tube as the X-ray source. A Symphony 7100 dissolution system (Distek, Inc., North Brunswick, NJ, USA) was used to study the dissolution behavior of the drug composites using a standard United States Pharmacopeia (USP) method (USP 41). The relative standard deviation of three repeat dissolution tests were below 4%.