Use of ATR-FTIR spectroscopy to study the diffusion of ethanol through glycerogelatin films

The use of ATR-FTIR spectroscopy to study the permeability of a glycerogelatin film is described. Measurement of the diffusion coefficient of ethyl alcohol-d in the film showed excellent reproducibility. Comparison of results from this technique with those previously obtained using an air-flow receptor phase diffusion cell show good agreement in terms of lag time assessed diffusion coefficients. ATR-FTIR spectroscopy revealed time-dependent changes in the composition of the glycerogelatin film during the diffusional process. It was also demonstrated that the concurrent assessment of both diffusant penetration and film composition is feasible.