In this study, graphene oxide(GO) was used as drug carriers to amorphize poorly watersoluble drugs via a co-spray drying process. Two poorly water-soluble drugs, fenofibrate and ibuprofen, were investigated. It was found that the drug molecules could be in the graphene nanosheets in amorphous or nano crystalline forms and thus have a significantly enhanced dissolution rate compared with the counterpart crystalline form. In addition, the dissolution of the amorphous drug enwrapped with the graphene oxide was higher than that of the amorphous drug in activated carbon (AC) even though the AC possessed a larger specific surface area than that of the graphene oxide. The amorphous formulations also remained stable under accelerated storage conditions (40°C and 75% relative humidity) for a study period of 14 months. Therefore, graphene oxide could be a potential drug carrier and amorphization agent for poorly water-soluble drugs to enhance their bioavailability.

Abstract
 1. Introduction
 2. Experimental
  2.1. Co-spray drying
  2.2. Powder X-ray diffraction (XRD)
  2.3. Scanning electron microscopy (SEM)
  2.4. Differential scanning calorimetry andthermogravimetric analysis
  2.5. N2 adsorption
  2.6. Water vapor dynamic adsorption and desorption
  2.7. In vitro drug release studies
 3. Results and Discussion
 4. Conclusions
 References

• Shou-Cang Shen(Institute of Chemical and Engineering Sciences, A*STAR) Corresponding Author
• Wai Kiong Ng(Institute of Chemical and Engineering Sciences, A*STAR)
• Kumaran Letchmanan(Institute of Chemical and Engineering Sciences, A*STAR)
• Ron Tau Yee Lim(Institute of Chemical and Engineering Sciences, A*STAR)
• Reginald Beng Hee Tan(Institute of Chemical and Engineering Sciences, A*STAR, Department of Chemical and Biomolecular Engineering, The National University of Singapore) Corresponding Author