Emulsions are widely used across a variety of industries including agrochemicals, cosmetics and, importantly, pharmaceuticals. In recent years, emulsion-based adjuvants have been developed which have allowed for an improvement in tolerability and immune response to vaccinations. A combination of techniques such as chromatography, FTIR spectroscopy and density measurement are required to accurately quantify the water, oil and surfactant in an emulsion. Furthermore, all previously used methods require a calibration stage covering a concentration range suitable for the samples of interest.
This work aims to evaluate the use of thermogravimetric analysis (TGA) as a method for quantifying these three components in different types of veterinary adjuvant-based emulsions i.e., oil-in-water (O/W), water-in-oil (W/O) and double emulsion water-in-oil-in-water (W/O/W).