## 3 Results
### Skin Hydration  
Figure 3 shows the skin hydration value of the control and test groups before and after using the buccal collagen peptide film for 2 weeks and 4 weeks. No significant differences in the mean initial skin hydration (at 0 weeks) between the control group and the test group were found (43.97 \(\pm\) 13.32 AU vs. 42.03 \(\pm\) 11.00 AU, respectively). The mean skin hydration of the control group did not significantly change after 4 weeks. However, after 2 weeks,  
Figure 2: The concentration of collagen peptide in the buccal delivery film that permeated the buccal mucosa of swine as a function of the molecular weight and time. The changes were significantly different between 1 kDa and 3 kDa with \(p<0.001\) (***).  
the mean skin hydration of the test group significantly increased (_p_ < 0.001) by 16.56% compared with 0 weeks (48.99 \(\pm\) 9.19 AU), and there was a significant increase (_p_ < 0.001) in the test group compared with the control group (48.99 \(\pm\) 9.19 AU vs. 44.89 \(\pm\) 13.36 AU, respectively). The final measurements after 4 weeks showed a significant increase (_p_ < 0.001) in skin hydration in the test group by 33.43% compared with before the buccal collagen peptide film was used (56.08 \(\pm\) 9.38 AU). A significant difference (_p_ < 0.001) between the test group and the control group after 4 weeks was also shown (56.08 \(\pm\) 9.38 AU vs. 47.27 \(\pm\) 13.56 AU). Therefore, the buccal collagen peptide film improved skin hydration.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Parameters**} & \multirow{2}{*}{**Classification**} & \multicolumn{2}{c}{**Control Group (n = 21)**} & \multicolumn{2}{c}{**Test Group (n = 22)**} \\ \cline{3-6}  & & **Frequency (n)** & **Proportion (\%)** & **Frequency (n)** & **Proportion (\%)** \\ \hline \multirow{3}{*}{Age} & 30s & 0 & 0.00 & 1 & 4.55 \\  & 40s & 10 & 47.62 & 15 & 68.18 \\  & 50s & 11 & 52.38 & 6 & 27.27 \\ \hline \multirow{3}{*}{Skin type} & Dry skin & 15 & 71.43 & 11 & 50.00 \\  & Oily skin & 0 & 0.00 & 1 & 4.55 \\  & Normal skin & 4 & 19.05 & 3 & 13.64 \\  & Combination skin & 2 & 9.52 & 7 & 31.82 \\ \hline \multirow{3}{*}{Skin irritation reaction to the environment} & Yes & 0 & 0.00 & 0 & 0.00 \\  & No & 21 & 100.00 & 22 & 100.00 \\ \hline \multirow{3}{*}{Prickle and itch} & Yes & 0 & 0.00 & 0 & 0.00 \\  & No & 21 & 100.00 & 22 & 100.00 \\ \hline \multirow{3}{*}{Side effects} & Yes & 0 & 0.00 & 0 & 0.00 \\  & No & 21 & 100.00 & 22 & 100.00 \\ \hline \multirow{3}{*}{Change in skin condition during mensruation} & Yes & 1 & 4.76 & 1 & 4.55 \\  & No & 20 & 95.24 & 21 & 95.45 \\ \hline \multirow{3}{*}{Applied susscreen} & Daily use & 8 & 38.10 & 10 & 45.45 \\  & Used when going out & 13 & 61.90 & 12 & 54.55 \\ \cline{1-1}  & Not used & 0 & 0.00 & 0 & 0.00 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Characteristics of the volunteers.  
Figure 3: Skin hydration before (0 weeks) and after (2 and 4 weeks) using the collagen peptide buccal delivery film of the control group (gray) and test group (white). The boxplot shows the average (\(\bullet\)), median (—), and max–min whiskers (**I**). The changes were significantly different between the control and test groups, and before and after intake, with \(p\) < 0.001 (***).