The Institute of Pharmaceutical Innovation

Determination of the surface properties of two batches of salbutamol sulphate by inverse gas chromat

Determination of the surface properties of two batches of salbutamol sulphate by inverse gas chromatography

M. D. Ticehurst, R. C. Rowe and P. York

The surface properties of two batches of sambutamol sulphate, demonstrated to be chemically and structurally equivalent by FT-Raman spectroscopy and X-ray powder diffraction, were measured using a gas-solid chromatography technique, inverse gas chromatography (IGC). IGC was undertaken using polar and non-polar adsorbates (probes) at infinite dilution with salbutamol sulphate as the solid stationery phase. The retention behaviour of the probes was found to differ markedly between the two batches, implicating a profound difference in surface energetics. This was reflected in the differences in calculated dispersive component of surface free energy and acid-base parameters.