Evaluasi Perubahan Kadar Asam Kojat dalam Krim Pencerah Wajah pada Variasi Suhu dan Waktu Penyimpanan Menggunakan Spektrofotometri Visibel

Rafika Nur Hidayani — 2026-06-16

Kojic acid is one of the active ingredients commonly used in skin-lightening creams. This compound tends to be unstable at high temperatures, which can reduce its effectiveness. Indonesia’s tropical climate and high average temperatures exacerbate the risk of quality degradation. This study aims to analyze the effects of varying storage temperatures (4°C, 25°C, and 30°C) and storage time (Days 0, 3, 7, 14, and 28) on the decrease in kojic acid content in facial brightening creams, as well as to validate the visible spectrophotometric analysis method using FeCl₃ reagent based on linearity, accuracy, and precision parameters. Based on the validation parameters, the coefficient of determination (r²) for linearity was 0,9986, % recovery was 98,62%, and total %RSD was 3,91%. The results of the concentration determination tests showed a decrease in kojic acid levels during 28 days of storage under all temperature conditions (4°C, 25°C, 30°C). There was a significant difference in kojic acid levels among storage temperatures (Kruskal-Wallis, p = 0.003). The Dunn-Bonferroni test showed that 4°C differed significantly from 25°C and 30°C (p < 0.05), but not between 25°C and 30°C (p > 0.05). The Friedman test also showed a significant effect of time on the concentration at all three temperatures (p < 0.05). Thus, it is concluded that the higher the storage temperature and the longer the storage time, the greater the decrease in kojic acid content in the cream. These findings indicate that storage conditions can affect the quality of the active ingredient during product use by consumers; therefore, storage at a low temperature (4°C) is recommended to help maintain kojic acid levels in the cream formulation. Furthermore, the analytical method used met validation criteria, ensuring that the results obtained are scientifically reliable.

Formulasi dan Uji Antibakteri Sediaan Pasta Gigi Ekstrak Parijoto (Medinilla Speciosa) dengan Eggshell Hydroxyapatite (EHA)

Zaki Syariifuddin Taqiy — 2026-06-16

Dental caries is one of the dental and oral health problems related to the activity of bacteria such as Streptococcus mutans and Staphylococcus aureus. The use of fluoride as an active ingredient in toothpaste has several limitations, so the development of natural-based alternative ingredients is one approach that needs to be studied. This study aims to formulate and evaluate the physical stability and antibacterial activity of a toothpaste preparation combining parijoto fruit extract (Medinilla speciosa) and Eggshell Hydroxyapatite (EHA). The study was conducted experimentally using four formulas, namely F0 (without parijoto extract), F1 (10% parijoto extract), F2 (12.5% parijoto extract), and F3 (15% parijoto extract). Evaluation of the preparation includes organoleptic tests, phytochemical screening, homogeneity, pH, viscosity, foam height, and antibacterial activity tests using the well diffusion method against S. aureus and S. mutans bacteria. The results of phytochemical screening showed that parijoto fruit extract contains phenolic compounds, flavonoids, saponins, and tannins. The results of the viscosity test in F0, F1, F2, and F3 were 14070 cps ± 809.03, 46600 cps ± 866.54, 43090 cps ± 3136.61, and 41910 cps ± 2200.27, respectively. Variations in extract concentration significantly affect viscosity with viscosity statistics results (p <0.05). pH test results F0: 7.87 ± 0.5918, F1: 7.44 ± 0.3241, F2: 7.33 ± 0.4082, F3: 7.40 ± 0.1625, Foam height F0: 1.56 cm ± 0.40415, F1: 2.06 cm ± 0.05774, F2: 2.13 cm ± 0.11547, F3: 1.93 cm ± 0.11547. The results of the antibacterial test of Staphylococcus aureus showed an inhibitory value of F0 (negative control) of 1.66 cm ± 0.24664, positive control 1.63 cm ± 0.14433, F1 (10% extract) 1.60 cm ± 0.08660, F2 (12.5% extract) 1.83 cm ± 0.32145, F3 (15% extract) 1.70 cm ± 0.05. The comparison between groups did not have a significant value (p > 0.05). The results of the antibacterial test of Streptococcus mutans F0 (negative control) 1.53 cm ± 0.02886, positive control 1.66 cm ± 0.24664, F1 (10% extract) 1.45 cm ± 0.05, F2 (12.5% extract) 1.48 cm ± 0.10408, F3 (15% extract) 1.50 cm ± 0.05. The comparison between groups was not significant (p>0.05). Based on the results of the study, the combination of parijoto fruit extract and EHA can be formulated into a toothpaste preparation with good physical characteristics, but increasing the concentration of parijoto extract has not shown a significant effect on antibacterial activity compared to the control formula.

Journal of Pharmaceutical and Health Research

Evaluasi Perubahan Kadar Asam Kojat dalam Krim Pencerah Wajah pada Variasi Suhu dan Waktu Penyimpanan Menggunakan Spektrofotometri Visibel

Formulasi dan Uji Antibakteri Sediaan Pasta Gigi Ekstrak Parijoto (Medinilla Speciosa) dengan Eggshell Hydroxyapatite (EHA)