2.6. Dynamic Vapor Sorption

Dynamic vapor sorption (DVS) analysis was performed on the amikacin formulation using a DVS-1 (Surface Measurement Systems, Middlesex, United Kingdom). About 35 mg of sample was used for each run. Two different runs were made. Both runs started at 0% RH and increased the RH when the mass change per time interval (dm/dt) was below 0.0005%/min. During the first type of run, the RH was increased in steps of 10% to a maximum of 90%, after which the RH was decreased back to 0% RH with the same steps. During the second type of run the RH was increased to 40% in one step and was decreased back to 0% after that.