In vitro release studies
The free OMC gel formulation showed a higher steady-state flux diffusion value of 6.3 ± 1.21 μg/cm2/hour, releasing higher amounts of filter to the receptor solution (24.06 ± 3.62 μg/cm2) at the end of 180 minutes (Figure 5). The higher standard error values indicate that there was greater variability between the six cells used.
The liposome/OMC gel formulation had a steady-state flux diffusion value of 3.9 ± 0.33 μg/cm2/hour and released 14.70 ± 0.98 μg/cm2 of OMC after 180 minutes (Figure 5). This formulation showed a low standard deviation, indicating small variability between the six cells used. Statistical analysis showed that there was a significant difference between the steady-state flux diffusion values of the liposome/OMC and conventional gel formulations. The amounts of sunscreen released per area were significantly different from the 90-minute point (Figure 4), indicating that the two formulations release OMC in a different manner and that the liposome is able to modify OMC release.