BACKGROUND: The bark of pulai (Alstonia scholaris [L] R.Br.) by the Gorontalo community is used for powder preparation (as a wedding ceremony custom), containing flavonoid compounds that function as sunscreens. Thus, the bark of pulai can be made in pharmaceutical preparations in the form of lotion dosage forms. AIM: This study aims to determine the SPF value of the lotion preparation of pulai bark extract. There are four formulas, formula F0 (lotion base), formula F1 (0.5%), formula F2 (1%), formula F3 (2%). METHODOLOGY: Physical evaluation of lotion preparations was carried out with organoleptic test parameters, spreadability, homogeneity, stability, pH. The SPF value of the lotion preparation was tested using the ultraviolet-Vis Spectrophotometry method with a wavelength of 290–400. RESULTS: The results of the physical evaluation of the organoleptic test and the homogeneity test were obtained that the lotion had a clear white color (F0), light yellow (F1), yellow (F2), dark yellow (F3), a characteristic smell of olive oil, and the four formulas had a thick and homogeneous consistency. The dispersion power of F0, F1, and F2 does not meet the requirements of the dispersion test value except F3. The three lotion formulations F1, F2, and F3 showed physical instability, except for F0 (lotion base). The pH of the lotions of the four formulas was in the range that was in accordance with the standard of topical preparations. CONCLUSION: The determination of the SPF value in the formulas F1, F2, and F3, respectively, was 3.3427 (minimum protection), 4.7752 (medium protection), and 5.0968 (medium protection).