4.7. In vitro drug release from cubosomes
In vitro release profile of ALA from cubosomes was performed in
hydro-alcoholic solution using the paddle over disk method. For
cubosomes of D1, 97.54% of the drug was released within 6 h. For
cubosomes of D2, 94.18% of the drug was released within 6 h.
For cubosomes of D3, 90.04% of the drug was released within 6 h
(Fig. 8). The results indicated a trend toward a decrease in release
rate with increasing GMO concentration, although this was not statistically
significant (p > 0.05). This may be attributed to the high
solubility of ALA in GMO. The release rate constants and correlation
coefficients were calculated after fitting the release data to
square root Higuchi model and are summarized in Table 5. The correlation
coefficients (R) calculated for each formulation were above
0.99, which indicated that in vitro drug release profiles of ALA
cubosomes fit well with the square root Higuchi model. Hence formulation
D3 was selected as the optimized formulation by virtue
of slowest drug release and maximum entrapment efficiency