Physical Stability Evaluation of Night Cream Preparations from Beauty Clinics in Pekanbaru, Indonesia

Night creams are widely used in facial skincare and should maintain appropriate physical characteristics during storage and use. This study compared the preliminary physical stability profiles of night cream preparations obtained from five beauty clinics in Pekanbaru, Indonesia. Five samples, coded A–E, were evaluated for organoleptic characteristics, dispersion pH, emulsion type, macroscopic homogeneity, and visible phase separation. Freeze–thaw testing was conducted for four cycles, each consisting of storage at 4 ± 2°C for 48 h followed by 40 ± 2°C for 48 h. Creams B, C, and D retained their initial organoleptic characteristics. Cream A showed a colour change and a subjectively perceived consistency change, whereas Cream E showed a subjectively perceived consistency change at cycle IV. Measured dispersion pH values ranged from 5.55 to 6.64. At the end of testing, all samples were identified as oil-in-water emulsions, appeared macroscopically homogeneous, and showed no visible phase separation. Creams B, C, and D therefore showed better preliminary macroscopic physical stability than Creams A and E. However, these findings do not establish complete emulsion stability because rheological behaviour, microscopic structure, globule size, and globule-size distribution were not evaluated.