Preparation and characterization of streptomycin sulphate-loaded nanocapsule coated with chitosan and poly-γ-glutamic acid

To prolong streptomycin sulfate effective time,streptomycin sulphate-loaded nanocapsule coated with chitosan andγ-polyglutamic acid was prepared and characterized.The composite nanocapsule was prepared using a simple,mild ionic-gelation method,and streptomycin sulphate was loaded during gelating.The effects of streptomycin sulfate dosage and chitosan/poly-γ-glutamic acid mass ratio on the process of encystation were tested.The results indicated that loading efficiency increased with increasing of streptomycin sulfate dosage,encapsulation efficiency increased and loading efficiency decreased when the mass ratio of chitosan andγ-polyglutamic acid decreased.When the dosage of streptomycin sulfate was 10 mg,and the mass ratio of chitosan toγ-polyglutamic acid was 20:17,the highest encapsulation efficiency (85.2%) was gotten,and loading efficiency reached 46.8%.The Fourier transform infrared spectroscopy and differential scanning calorimetric analysis confirmed that streptomycin sulfate was loaded in nanocapsule,and the solid nanocapsule with average diameter 20-50 nm was observed under transmitted electronic microscopy.Sustained-releasing of streptomycin sulfate was observed under simulation releasing test.