NAG loaded emulgels were assayed and the results are reported in Table 3. Several skin test strips were also analyzed in order to evidence the release of NAG from the formulation towards the skin and the extent of the adsorption of NAG by the upper layers of the skin. As can be seen in Table 3 the recoveries from the skin
test strips were lower than 100% both in the case in which a NAG solution was applied on the skin and when the complete formulations were applied. The preliminary data obtained and presented in Table 3, although collected from a very limited number of samples, showed a relevant loss of NAG upon application on human
skin. This was considered likely to be due to a different extent of adsorption of NAG into the skin. These data need further study in
order to understand the behaviour of the NAG when released onto
the skin.