Although flowindexes were not altered by thermal stress consistency
indexes increased significantly (Table 3). It is widely
known that consistency indexes normally decrease during storage,
indicating instability (Martin et al., 1993; Korhonen et al.,
2001), but in our results the consistency index increased. It is
possible that this was due to the interaction of retinyl palmitate
and polyacrilamide, the vehicle polymer, as shown by an artifact
when the decomposition products were analyzed by mass
spectrometry (data not shown)