ALA were released within 8 h respectively and the difference was not statistically significant (p > 0.05). The release rate constants and correlation coefficients were calculated after fitting the release data to square root Higuchi model and are summarized in Table 6.
The correlation coefficients (R) calculated for each gel concentration
were above 0.99, which indicated that in vitro drug release
profiles of ALA from P407 gel fit well with the square root Higuchi
model