207
Microspheres were prepared by emulsion solvent evaporation method and evaluated for particle size , entrapment efficiency , buoyancy , and in vitro release ; and further characterized by powder X - ray diffraction , Fourier transform infrared spectroscopy , scanning electron microscopy , and differential scanning calorimetry .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 None