The individual formulations of heated and unheated BSA and buffer with and without the addition of polysorbate show no significant differences in their relaxation times. The T 1 and T 1⇢ relaxation time differences of sucrose and BSA (Figure ) are the same within the error of the measurement. This indicates that no phase separation takes place within the samples upon lyophilisation, but also that heating in F2 and F4 does not cause phase separation.