Glucose, lactose and saccharose solutions
Inactive ingredient (stabilizer in solutions)
Measuring cell: DSC821e with IntraCooler
Pan: Aluminum 40 µl, hermetically sealed
Sample preparation: One drop of solution is weighed into the pan using a fine pipette
DSC measurement: Cooling from 20 °C to -60 °C. The solution was then equilibrated for 5 minutes at -60 °C and finally heated at 5 K/min to 25 °C
Atmosphere: Air, stationary environment, no flow rate
The diagram shows the melting peaks of the different solutions. The dissolved substance behaves as an impurity and depresses the melting point of the solvent (water).
The onset temperatures of the melting peaks of the solutions and the heats of fusion are determined.
Sample | Onset, °C | Sample weight, mg |
---|---|---|
Glucose (20 weight %) | -7.4 | 20.067 |
Lactose (20 weight %) | -4.4 | 14.666 |
Saccharose (20 weight %) | -4.4 | 9.412 |
Saccharose (10 weight %) | -2.6 | 13.221 |
Saccharose (5 weight %) | -1.8 | 9.715 |
Saccharose (0.1 weight %) | -0.3 | 14.495 |
The higher the concentration of added sugar, the lower the onset temperature.
Melting Point Depression of Water, Sugar Solutions | Thermal Analysis Application No. HB822 | Application published in METTLER TOLEDO TA Application Handbook Pharmaceuticals