## 3 Results and Discussion
### HPLC-MS Method Validation
In order to evaluate the presence of signific  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Steeroid**} & \multicolumn{3}{c}{**Spiked**} & \multicolumn{3}{c}{**Recovery (\(\pm\)CV\%)**} & \multicolumn{3}{c}{**LOD (ng/mL)**} & \multicolumn{3}{c}{**LOQ (ng/mL)**} \\ \cline{2-10}  & **Concentration** & **(ng/mL)** & **Cream A** & **Cream B** & **Serum** & **Cream A** & **Cream B** & **Serum** & **Cream A** & **Cream B** & **Serum** \\ \hline \multirow{3}{*}{BM} & 0.3 & 88.1 (\(\pm\)4.3) & 65.3 (\(\pm\)5.5) & 70.2 (\(\pm\)9.2) & & & & & & \\  & 0.5 & 95.1 (\(\pm\)2.6) & 71.2 (\(\pm\)7.8) & 78.2 (\(\pm\)3.4) & & & & & & \\  & 12-V & 10 & 83.5 (\(\pm\)5.2) & 62.5 (\(\pm\)7.7) & 76.7 (\(\pm\)5.7) & & & & & & \\  & 20 & 84.9 (\(\pm\)5.3) & 86.6 (\(\pm\)4.9) & 73.5 (\(\pm\)3.7) & & & & & & \\ \hline \multirow{3}{*}{BC} & 0.3 & 91.5 (\(\pm\)8.2) & 120.8 (\(\pm\)9.6) & 108.7 (\(\pm\)9.1) & & & & & & \\  & 0.5 & 89.1 (\(\pm\)4.3) & 109.9 (\(\pm\)7.7) & 103.2 (\(\pm\)6.6) & 0.07 & 0.15 & 0.28 & 0.2 & 0.49 & 0.51 \\  & 10 & 95.3 (\(\pm\)8.6) & 115.7 (\(\pm\)6.7) & 105.1 (\(\pm\)3.6) & & & & & & \\  & 20 & 99.8 (\(\pm\)8.9) & 113.5 (\(\pm\)5.4) & 112.9 (\(\pm\)3.9) & & & & & & \\ \hline \multirow{3}{*}{BCDP} & 0.3 & 112.1 (\(\pm\)7.1) & 101.4 (\(\pm\)7.5) & 77.8 (\(\pm\)8.2) & & & & & & \\  & 0.5 & 101.1 (\(\pm\)8.4) & 99.6 (\(\pm\)3.9) & 80.6 (\(\pm\)7.5) & & & & & & \\  & 10 & 105.1 (\(\pm\)8.6) & 93.8 (\(\pm\)4.1) & 75.0 (\(\pm\)8.3) & & 0.02 & 0.04 & 0.48 & 0.08 & 0.13 & 1.16 \\  & 20 & 111.8 (\(\pm\)4.4) & 98.6 (\(\pm\)8.4) & 85.3 (\(\pm\)9.1) & & & & & & \\ \hline \multirow{3}{*}{MP} & 0.3 & 76.0 (\(\pm\)3.4) & 79.7 (\(\pm\)2.9) & 79.5 (\(\pm\)7.3) & & & & & & \\  & 0.5 & 70.3 (\(\pm\)8.2) & 85.8 (\(\pm\)6.4) & 73.5 (\(\pm\)8.3) & & & & & & \\  & 10 & 79.2 (\(\pm\)10.1) & 81.9 (\(\pm\)4.6) & 71.3 (\(\pm\)8.4) & & & & & & \\  & 20 & 72.4 (\(\pm\)3.7) & 83.4 (\(\pm\)8.8) & 75.3 (\(\pm\)5.6) & & & & & & \\ \hline \multirow{3}{*}{BD} & 0.3 & 77.4 (\(\pm\)9.2) & 78.0 (\(\pm\)7.2) & 106.0 (\(\pm\)4.6) & & & & & & \\  & 0.5 & 72.4 (\(\pm\)6.2) & 75.3 (\(\pm\)7.7) & 115.2 (\(\pm\)7.1) & 0.12 & 0.16 & 0.13 & 0.42 & 0.53 & 0.45 \\  & 10 & 75.0 (\(\pm\)5.5) & 82.8 (\(\pm\)9.2) & 110.3 (\(\pm\)9.1) & & & & & & \\  & 20 & 79.0 (\(\pm\)9.8) & 79.2 (\(\pm\)7.6) & 111.2 (\(\pm\)8.8) & & & & & & \\ \hline \multirow{3}{*}{FN} & 0.3 & 72.4 (\(\pm\)9.8) & 102.0 (\(\pm\)7.8) & 96.0 (\(\pm\)4.8) & & & & & & \\  & 0.5 & 75.4 (\(\pm\)8.9) & 106.0 (\(\pm\)8.8) & 106.5 (\(\pm\)4.1) & 0.04 & 0.08 & 0.13 & 0.13 & 0.25 & 0.43 \\ \cline{1-1}  & 10 & 82.5 (\(\pm\)9.6) & 106.7 (\(\pm\)9.1) & 103.3 (\(\pm\)8.1) & & & & & & \\ \cline{1-1}  & 20 & 79.0 (\(\pm\)5.8) & 105.4 (\(\pm\)8.3) & 99.2 (\(\pm\)8.4) & & & & & & \\ \hline \multirow{3}{*}{FM} & 0.3 & 93.5 (\(\pm\)3.9) & 74.2 (\(\pm\)8.8) & 99.9 (\(\pm\)5.5) & & & & & & \\  & 0.5 & 89.4 (\(\pm\)4.3) & 74.8 (\(\pm\)9.9) & 102.0 (\(\pm\)7.5) & & & & & & \\ \cline{1-1}  & 10 & 101.1 (\(\pm\)4.9) & 76.7 (\(\pm\)2.8) & 109.9 (\(\pm\)8.4) & & & & & & & \\ \cline{1-1}  & 20 & 96.6 (\(\pm\)5.9) & 72.1 (\(\pm\)3.7) & 103.54 (\(\pm\)8.2) & & & & & & & \\ \hline \multirow{3}{*}{DM} & 0.3 & 85.7 (\(\pm\)6.6) & 94.1 (\(\pm\)8.8) & 96.1 (\(\pm\)8.8) & & & & & & & \\ \cline{1-1}  & 0.5 & 91.4 (\(\pm\)6.9) & 82.9 (\(\pm\)8.4) & 91.7 (\(\pm\)7.2) & & & & & & & \\ \cline{1-1}  & 10 & 79.1 (\(\pm\)7.1) & 93.8 (\(\pm\)9.4) & 93.7 (\(\pm\)6.2) & & & & & & & \\ \cline{1-1}  & 20 & 89.7 (\(\pm\)8.3) & 89.0 (\(\pm\)4.8) & 87.6 (\(\pm\)4.4) & & & & & & & \\ \hline \hline \end{the obtained results and the real concentration values, paired _t_-tests were performed, with no critical issues found for any of the analyzed samples (n = 2 and \(p\) = 0.01). It is important to point out that there is not a minimum established value for recovery since an analytical method with a low recovery could be suitable for a certain analyte if the sensitivity of the detection technique is high enough. Nevertheless, recovery of the analyte should be precise, reproducible, and consistent over the calibration range.